Certain 1-azolylindol-3-ylaliphatic acids



United States Patent 3 275 CERTAIN 1-AZOLY}1D)L-3-YLALIPHATIC ID Tsnng-Ying Shen, Westfield, N.J., assignor to Merck & Co., Inc., Rahway, N.J., a corporation of New Jersey No Drawing. Filed Nov. 4, 1963, Ser. No. 321,328 20 Claims. (Cl. 260-302) This application is a divisional continuation-in-part of my copending application, Serial No. 164,615, filed January 5, 1962, which was a continuation-in-part of my application, Serial No. 97,434, filed March 22, 1961, now abandoned.

This invention relates to new chemical compounds. More particularly, it relates to a new class of compounds of the indole series. Still more particularly, it is concerned with new a-(3-indolyl)-lower aliphatic acids having an aromatic carboxylic acyl radical of less than three fused rings attached to the nitrogen atom of the indole ring. It is concerned further with salts, esters and amide derivatives of such compounds. It relates also to the synthesis of such substances.

The new aroyl and heteroaroyl indolyl aliphatic acid compounds of this invention have the general structural formula:

a Rs-QTF (I) H- C O M r- R4 o is in which R may be oxazole, thiazole, imidazole, isooxazole, isothiazole, pyrazole, oxadiazole, thiadiazole or a substituted oxazole, thiazole imidazole, isoxazole, isothiazole, pyrazole, oxadiazole or thiadiazole radical in which thesubstituents may be halogen, lower alkyl, lower alkylthio, lower alkenylthio, halogeno lower alkenylthio, di(lower alkyl)amino lower alkylthio, benzyl, phenyl, hydroxy lower alkyl, lower alkoxy lower alkyl, nitrophenyl, anilino, halogenophenyl, sulfamyl, lower alkanoyl, pyridyl carboxy, carboxamido, cyano, carb-lower alkoxy, cyanomethyl, mercapto, nitro, amino, di(lower alkyl) amino, lower alkylarnino, lower alkanoylamino, benzyloxy, aminolower alkyl, hydroxy, halogeno-lower alkanoyl, and dilower alkylamino lower alkyl;

R may be hydrogen, lower alkenyl or lower alkyl;

R may be hydrogen, lower alkoxy, fluorine, lower alkyl or trifluoromethyl;

R may be hydrogen, lower alkyl, lower alkoXy, nitro, amino, lower alkylamino, di(lower alkyl)amino, lower alkanoylamino, lower alkanoyl, bis(hydroxy lower alkyl) amino, 1 pyrrolidino, 4 methyl 1 piperizinyl, 4-morpholinyl, cyano, amino lower alkyl, di(lower alkyl) amino lower alkyl, trifluoromethyl, halogen, di(lower alkyl) sulfamyl, benzylthio, lower alkylbenzylthio, lower alkoxy benzylthio, halogenobenzylthio, benzyloxy, lower alkylbenzyloxy, lower alkoxybenzyloxy, halogenobenzyloxy, lower alkenyl, lower alkenyloxy, l-azacyclopropyl, cyclopropylmethyloxy or cyclobutylmethyloxy;

and M may be OH, NH lower alkoxy, benzyloxy, OZ

3,275,644 Patented Sept. 27, 1966 ice Where Z is a cation or OY Where Y is the structure:

a R5 -(BHC 0- \N/-R2 R4 In the most preferred compounds of the invention, R is a lower alkyl, lower alkoXy, nitro, amino, or substituted amino. Examples of the alkyl and alkoxys are methyl, ethyl, propyl, t-butyl, methoxy, ethoxy, i-propoxy and the like. R is not limited to this class of substituents,

however, and may, if desired, represent substituents such as hydrogen, aryl, aryloxy, hydroxy, mercapto, halo, pseudohalo such as CF CHF or other haloalkyls, nitro, amino, alkylamino, acylamino, haloalkyl, cyano, sulfamyl, sulfoxide, aminomethyl, substituted aminomethyl, carboxy, carboalkoxy groups.

A critical feature of the new compounds described herein is the presence of an aroyl radical of the azole carboxylic acid class attached to the N-1 position of the indole.

These acyl groups may be further substituted in the aromatic ring with hydrocarbon groups such as lower alkyl, benzyl, phenyl, or with functional substituents such as nitrophenyl, cyano lower alkyl. Thus, suitable aroyl substituents are the oxazole, thiazole imidazole, isooxazole, isothiazole, pyrazole, oxadiazole or thiadiazole carboxy groups. These will be referred to herein collectively as azole carboxy groups. The aromatic rings of such groups may contain, and in the preferred compounds do contain, at least one functional substituent. This sub stituent may be a hydroxy or an etherified hydroxy (hydrocarbonoxy) group such as a lower alkoxy, e.g., methoxy, ethoxy, isopropoxy, propoxy, an alkenyloxy such as allyloXy, an aryloxy or aralkoxy group, e.g., phenoxy, benzyloxy, hydroxy lower alkyl, lower alkoxy lower alkyl and the like. It may be a nitro radical, a halogen such as chlorine, bromine, iodine or fluorine, as amino group or a substituted amino group, representative examples of which might be mentioned are acylamino, (e.g., lower alkanoylamino, benzoylamino), amine oxide, ketimines, urethanes, lower alkylamino, lower dialkylamino anilino, amidine, acylated amidines, hydrazine or a substituted hydrazine, alkoxyamines, amino lower alkyl, dilower alkylamino lower alkyl, and sulfonated amines. Further, it may be a mercapto or a substituted mercapto radical of the type exemplified by alkylthio groups such as methylthio, ethylthio, and propylthio and arylthio or aralkylthio groups, e.g., benzylthio and phenylthio, carboxy lower alkylthio, lower alkenylthio, halogeno-lower alkenylthio or dilower alkylamino lower alkylthio. The N-l aroyl radical may, if desired, be haloalkylated, as with a trifluoromethyl, trifluoroethyl, perfluoroethyl, ,8- chloroethyl or like substituent, acylated as with lower alkanoyl (acetyl, propionyl), benzoyl, phenylacetyl, halogeno lower alkanoyl, pyridine carboxyl, and like acyl groups, or it may contain a haloalkoxy or haloalkylthio substituent. In addition, the invention embraces compounds wherein the aroyl radical contains a sulfamyl, cyano, sulfonamido or dialkylsulfonamido radical. Further, it may contain a carboxy substituent, or a derivative thereof, such as an alkali metal salt or a lower alkyl ester of the carboxy radical, (i.e., a carb lower alkyl) thiocarbamyl, an aldehyde, azide, amide, hydrazide and the like, or an aldehyde derivative of the type represented by acetals or thioacetals. In the preferred compounds, the N-l aroyl radical is benzoyl and the functional substituent is in the para position of the six-membered ring.

The a-(3-indolyl)-aliphatic acids described herein are preferably lower aliphatic acids such as a-(3-indolyl) derivatives of acetic, propionic, butyric, valeric and like acids. Lower alkyl esters, salts and the amides of such aliphatic acids represent an additional aspect of the invention. The esters are important intermediates in the syntheses of the free acids, and in many cases are them selves of importance as end products. The preferred esters are the lower alkyl esters such as the methyl, ethyl, propyl or t-butyl compounds and the benzyl, p-halobenzyl and like esters.

The salts of these new a-(l-azolyl carboxyl-3-indolyl)- lower aliphatic acids can be obtained by treatment of the free acid with base under mild conditions. In this manner there may be obtained alkaline metal salts such as the sodium and potassium, the aluminum or magnesium salts or salts of alkaline earth metals, examples of which are barium and calcium. Salts of organic amines such as dimethylamine, morpholine, methyl cyclohexylamine or flucosamine may be obtained by reacting the acid with the appropriate organic base. The amides included within this invention are conveniently synthesized by first preparing the amide of an a-(3-indolyl)-lower aliphatic acid unsubstituted at the 1-position and then acylating said compound by the process described hereinbelow. Such amides are conveniently obtained by reacting the free acid with urea or treating the appropriate acid chloride with ammonia.

The 2-position of the indole ring nucleus (R in the above formula) may be hydrogen although it is preferred that there be present at this position of the molecule a hydrocarbon radical having less than nine carbon atoms. Lower alkyl groups such as methyl, ethyl, propyl or butyl are the most satisfactory, but lower alkenyl radicals also can be used.

The following compounds are representative of those contemplated by this invention and which may be prepared by the procedure discussed hereinbelow:

methyl a-[ 1-(5-chloro-Z-thiazolylcarboxy) -2-methyl- -methoXy-3-indolyl] -acetate,

methyl oc[ 1- (2-benzyl-5-chloro-4-oxazolylcarboxy 2,5-dimethyl-3-indolyl]-acetate,

methyl a-[1-(Z-methylthio-S-methyl-l-imidazolylcarboxy) -2-methyl-5-methoXy-3-indolyl] -acetate,

a-[ l- 5-nitro-4-imidazolylcarboxy) -2-methyl-5-methoxy- 3-indolyl]-propionic acid,

oc- 1- S-phenyl-Z-oxazolyl carboxy) -2-methyl- 5-methoxy-3-indolyl] -acetamide,

a-[ 1- 4-methyl-5-thiazolylcarboxy-2-methyl- 5-methoXy-3-indolyl] -acetamide,

ethyl a-[1-(3-acetyl-S-thiazolylcarboxy)-2-methyl- 5-methoxy-3-ind-olyl]-propionate,

benzyl o-[1-(2-oxazolylcarboxy)-2-methyl- 5-methoXy-3-indolyl] -acetate,

and the like. The a-(l-azolyl carboxy-3-indolyl)-lower aliphatic acids and derivatives thereof described herein are synthesized by acylation of the x-(3-indolyl)-lower aliphatic acid, ester or amide having the desired substituents at the 2- and 5-positions of the ring nucleus. It is preferred to carry out the acylation on an ester or amide derivative of the lower aliphatic acid. In those cases where the free acid is desired, the ester may be converted under suitable reaction conditions to the free acid. It has been observed that the l-aroyl or heteroaroyl substituent is easily hydrolyzed under conditions normally employed for saponification of an ester to the free acid. For this reason, care must be taken in converting the a-(1-acyl-3- indolyl)-lower aliphatic acid esters to the corresponding free acids. It has been found that one convenient method of accomplishing this conversion comprises acylation of the benzyl ester and subsequent hydrogenolytic removal of the benzyl ester. Alternatively, other esters such as the t-butyl esters, which are amenable to selective removal by other treatment, such as heating above 210 C. or by heating at 25110 C. in the presence of a catalytic amount of an aryl sulfonic acid or other acids may be utilized. When, instead of an ester, the amides of these acids are prepared, the free acids are formed by reaction of the amides with a stoichiometric quantity of nitrous acid in an inert solvent.

The acylation reaction is conducted by one of two methods. One such consists in treating the a-(3-ind-olyl)- lower aliphatic acid starting material with an alkali metal hydride such as sodium hydride to form e.g., a sodium salt and then intimately contacting said salt with an azole carboxylic acid halide in an anhydrous solvent medium. It is preferred to employ solvents such as dimethylformamide, dimethylformamide-benzene, benzene, toluene, or xylene. It is preferred to carry out the acylation at about room temperature although lower temperatures may be employed if the particular reactants are unduly susceptible to decomposition.

An alternative method and (with these basic heteroaroyl acids) greatly preferred method of acylating the 1-position is by use of a phenolic ester of the acylating acid, such as the p-nitrophenyl ester. This latter is prepared by mixing the acid and p-nitrophenol in tetrahydrofuran and adding dicyclohexyl carbodiimide in tetrahydrofurane slowly. The dicyclohexylurea which forms is removed by filtration and the nitrophenylester is recovered from the filtrate. Alternatively, there can also be used the anhydride, azide or thiophenolic ester of the acylating acid. Whichever is used, the acylation of the a-(3-indolyl)-lower aliphatic acid starting material is achieved by forming a sodium salt of said material with sodium hydride in an anhydrous solvent and adding the nitrophenylester. Because of the basic character of these aroyl acids this method is preferred over the acid chloride method for ozolyl carboxylic acids.

The a-(1-acy1-3-indolyl)-lower aliphatic acid compounds of this invention have a high degree of antiinflammatory activity and are effective in the prevention and inhibition of granuloma tissue formation. Certain of them possess this activity in high degree and are of value in the treatment of arthritic and dermatological disorders and in like conditions which are responsive to treatment With anti-inflammatory agents. In addition, the compounds of this invention have a useful degree of antipyretic activity. For these purposes, they are normally administered orally in tablets or capsules, the optimum dosage depending, of course, on the particular compound being used and the type and severity of infection being treated. Although the optimum quantites of these compounds of this invention to be used in such manner will depend on the compound employed and the particular type of disease condition treated, oral dose levels of preferred compounds in the range of 1.0-2000 mg. per day are useful in control of arthritic conditions, depending on the activity of the specific compound and the reaction sensitivity of the patient.

The indolyl aliphatic acid compounds employed as starting material in the reaction discussed above, and having the formula:

a R oHooE where R R R and R have the previously defined meanings and E is a hydrocarbonoxy radical having less than nine carbon atoms or NH may be synthesized in various ways. When R is hydrogen or methyl, it is preferred to form such compounds by reacting together an appropriately substituted phenylhydrazine and a substituted levulinic ester or amide to form an intermediate phenylhydrazone which cyclized under the reaction conditions to the indole compound where R R R and E are as above, and R is hydrogen or methyl. The reaction is normally carried out in a lower alkanol such as methanol, ethanol, isopropanol or butanol containing an acid such as hydrochloric, hydro- 'bromic, sulfuric or acetic acid or in aqueous mineral acid such as concentrated hydrochloric, hydrobromic, sulfuric or acetic acid, or other Lewis acids such as ZIICIZ, BF ZnCl; and the like. The acid serves as a catalyst in the condensation and ring closure reactions leading to the 1- unsubstituted indole. When the substituted levulinic esters are used, the nature of the ester is not critical, although it is preferred to utilize a lower alkyl ester, e.g., the methyl, ethyl, propyl, isobutyl or isopropyl compound. To avoid the possibility of transesterification the alcohol used as the solvent medium is preferably the same as the alcohol moiety of the ester. When R is hydrogen, it is convenient to employ the aldehyde in the form of an acetal, e.g., methyl 'y, y-dimethoxy butyrate. An acid addition salt of the phenylhydrazine reactant, for example the hydrochloride, is normally preferred over the flee base for practical reasons, although such salts and the base are equivalent in the reaction itself.

Formation of the a-(3-indolyl)-aliphatic acid, or ester thereof, is brought about at elevated temperatures, good results being obtained by refluxing the reaction mixture for at least about 15 minutes. Longer reaction times are not harmful and may be used if desired. The desired compound is recovered from the reaction mixture and purified by techniques such as solvent extraction, chromatography and/ or distillation. Since the l-unsubstituted esters are low melting solids, they are conveniently purifled by distillation under reduced pressure. They are saponified by treatment with an alkali metal hydroxide.

The substituted phenylhydrazines employed as one of the starting materials in this synthesis are prepared by known methods. One convenient method is by diazotization of the appropriately substituted aniline to give the diazo compound, treatment of the latter with stannous chloride to form a tin complex, and decomposition of this complex to the phenylhydrazine with sodium hydroxide.

The l-acyl group in et-(l-acyl-3-indolyl) aliphatic acids and esters of this invention are, as has been mentioned earlier, easily hydrolyzed under the conditions normally used to saponify an ester. For this reason, the benzyl ester of the intermediate a-(1-unsubstituted-3-indolyl) acids are a convenient starting material. These are obtained by forming the free et-(l-unsubstituted-3-indo1yl) aliphatic acid and esterifying this with benzyl alcohol in an inert solvent with an acid catalyst (sulfuric, aryl sulfonic acids, etc.). Alternatively, the intermediate benzyl ester is synthesized directly by using the benzyl ester of the proper levulinic acid in the original synthesis of the indole ring, or is formed by base catalyzed ester exchange from other esters. After acylation of the indole nitrogen of these benzyl ester group can be removed clearly by hydrogenolysis, a process which leaves the l-acyl group untouched.

Alternatively, it is possible first to produce an indole of the formula:

N/ Ra 1'1 where R R and R have the same meaning as before, and then to introduce the carboxylic acid residue at the 3- position. This is accomplished by treating the indole of the above formula under Mannich reaction conditions with formaldehydedialkylamine to produce a substituted gramine, subsequently reacting this latter compound with an alkali metal cyanide in a lower alkanol, and finally hydrolyzing with a strong base such as a sodium or potas sium hydroxide.

While this method of introducing the aliphatic acid residue at the 3-position after elaboration of the indole ring is, of course, generally applicable to compounds having the structure shown above, it is particularly useful for making compounds of this invention wherein R is an alkyl radical other than methyl, such as the Z-ethyl, 2-propyl, 2-allyl and like substances. Compounds of the above formula, unsubstituted in the 3- position, are readily prepared following the procedures set forth in columns 2 and 3 of US. Patent No. 2,825,734. Products where R is acyloxy, halo, cyano, carboxy, carbalkoxy, alkyl, aryl, aralkyl, nitro or hydrocarbonoxy are prepared via the synthesis beginning from a substituted Z-nitro benzaldehyde or Z-nitrotoluene.

The synthesis of various compounds of this invention having on the indole ring system a S-Substituent which has a nitrogen attached to the monocyclic ring of the indole is generally based on the 5-nitro compound. This is transformed into the desired 5-substituent. Such trans formation may be before or after acylation of the 1- position, depending on the extent to which the desired 5- substituent may interfere with the acylation. If such interference is possible, the l-acylation should be carried out on the 5-nitro indole and the nitro later transformed into the desired 5-substituent. Such transformation can be carried out in a number of ways. Reduction of the S-nitro groups gives a S-amino group. Reaction of the amino with alkyl halides gives mono and dialkyl amino groups. If the alkyl halide is a dihaloalkylene group (e.g., 1,4-dibrornobutane) a heterocyclic ring (e.g., pyrrolidino) is formed. Similarly, bis(B- chlorethyl) ether will give an N-morpholino compound. Alkylation can also be carried out simultaneous with reduction, as e.g., with formaldehyde and Raney nickel and hydrogen. Acylation can similarly be carried out on the S-amino compounds or on the S-nitro (with simultaneous reduction) to give S-acylamido compounds. The S-amino group can be reacted With isocyanates to give S-ureido compounds.

EXAMPLE 1 A. Ethyl O6 (2 methyl-S-meth0xy-3-ind0lyl)-pr0pi0- nate.-A solution of 25 g. of p-methoxyphenylhydrazine hydrochloride and 20 g. of ethyl levulinate in 250 ml. of 2 N ethanolic hydrochloride is heated on a steam bath for a few minutes. An exothermic reaction takes place with the separation of ammonium chloride. The reaction flask is removed from the steam bath and the mixture allowed to reflux gently until the initial reaction subsides. The mixture is again heated on a steam bath under reflux for 30 minutes, and then concentrated in vacuo to a volume of about ml. The concentrate is diluted with about 400 ml. of water and extracted with ether. The resulting ethereal extract is washed with a saturated solution of sodium bicarbonate, and with water, and dried over anhydrous sodium sulfate. The dried solution is filtered and evaporated to a dark brown syrup which is purified by chromatography over about 1 lb.

of acid-washed alumina in a 2%" ID. column using mixtures of ether and petroleum ether (v./v. 1:9 to 1:1) as eluent. The light yellow syrup so obtained is distilled in a short-path distillation apparatus and the product collected at B1. 150l53 C. (0.25 mm.). The distillate of ethyl ot-(2-methyl-5-methoxy-3-indolyl)-propionate crystallizes o-n trituration with petroleum ether, MP. 53-555 C. On crystallization from a mixture of ether and petroleum ether the melting point is unchanged.

Calcd. for C H O N: C, 68.94; H, 7.33; N, 5.36. Found: C, 69.23; H, 7.31; N, 5.60.

When the methyl, propyl, isopropyl or benzyl ester of tat-methyl levulinic acid is employed in the above reaction in place of the ethyl ester, there is obtained methyl a- (2 methyl 5 methoxy 3 indolyl) propionate, propyl cc (2 methyl 5 methoxy 3 indolyl) propionate, isopropyl a (2 methyl 5 methoxy 3 indolyl) propionate, or benzyl a (2 methyl 5 methoxy 3 indolyl) propionate, respectively. Alternatively, when an ester of levulinic acid is used as starting material in the above process, the corresponding ester of a u-(2-methyl-5-methoxy-3-indolyl)-acetic acid is obtained.

B. Ethyl or-(2,5-dimethyl 3 indolyl) prpi0nate. 20 g. of p-methylphenylhydrazine hydrochloride and 20 g. of ethyl ot-methyl levulinatc are added to 250 ml. of 2 N ethanolic hydrogen chloride and the mixture warmed until reaction sets in. After the initial exothermic reaction stops, the mixture is refluxed for about /2 hour and then concentrated in vacuo to about ,5, volume. 400 ml. of Water are added and the aqueous solution extracted With ether. The ether extracts are 'washed with sodium bicarbonate solution, and with water, then dried over sodium sulfate. The ether solution is concentrated to a small volume in vacuo and chromatographed over acid-washed alumina (1 lb. of alumina in a 2%" ID. column). The material eluted with ether-petroleum ether (v./v. 9:1 to 1:1) is distilled in a shortpath distillation apparatus. Ethyl a-(2,5-dimethyl-3-indolyl)- propionate distills at ISO-170 (bath temp.)/1 mm., and crystallizes on trituration with petroleum ether, MP. 88- 88.5 C.

When a lower alkyl or benzyl levulinate is employed in place of ethyl a-methyl levulinate, lower alkyl or benzyl (2,5-dimethyl-3-indolyl)-acetate is produced.

EXAMPLE 2 Methyl a-[I (-chZora-2-thiaz0lylcarboxy)-2-methyl-5- methoxy-S-indolyl]-pr0pi0nate A suspension of 2.3 g. (0.046 m.) of 50% sodium hydride-mineral oil in 250 ml. of dimethylformamide is stirred for minutes under nitrogen with ice-cooling. Then 8.64 g. (0.035 m.) of ethyl a-(2-methyl-5-methoxy- 3-indolyl)-propionate is added and the mixture stirred for 20 minutes. 5-ch1oro-2-thiazolylcarboxy chloride (0.05 mole) in 50 ml. of dimethylformamide is added dropwise over a period of minutes. The mixture is stirred in an ice-bath for 5 hours under nitrogen. It is then poured into a mixture of 500 ml. of ether, 5 ml. of acetic acid and 1 l. of iced water. The organic products are extracted with 3 x 300 ml. of ether. The ether solutions are combined and washed with a large quantity of water, and dried over sodium sulfate. The solution is filtered, evaporated to near dryness and the residue charged onto a 300 g. alumina column. The ethyl oc- 1- 5 -chloro-2-thiazolylcarboxyl -2-methyl-5 -methoxy-3-indolyl]-propionate is eluted with 10% ether in petroleum ether. It is obtained on concentration of the eluates to dryness.

The 5-chloro-2-thiazolyl chloride starting material is obtained by heating a mixture of 0.15 mole of 5-chloro- 2-thiazole carboxylic acid and 0.18 m. of thionyl chloride on a steam bath for'l hour. About 20 ml. of benzene is then added and boiled ofl. The remaining is diluted with petroleum ether. chloride hydrochloride separates.

When methyl (2-methyl-5-methoxy-3-indolyl)-acetate is employed as the starting material in the above process, there is obtained methyl[1-(5-chloro-2-thiazolyl carbonyl -2-methyl-5 -methoxy-3 -indolyl] -acetate.

When pyrazole-l-carboxy chloride is used in the above procedure in place of 5-ch1oro-2-thiazolyl carboxy chloride, there is obtained ethyl]1-(1-pyrazolylcarboxy)-2- methyl-5methoxy-3-indolyl] propionate.

EXAMPLE 3 Methyl [I (4 thiazolyl carbonyl) 2 methyl 5 meth0xy-3-ind0lyl] acetate A. pNITR OP HENYL--THIAZOLYL CARB OXYLATE In a 500 m1. round bottom flask (all equipment flame dried) is added 13.9 g. of p-nitrophenol and 12.9 g. of thiazole-4-carboxylic acid in 250 ml. dry tetrahydrofuran. Through a dropping funnel is added over 30 minutes 20.6 g. of dicyclohexycarbodiimide in ml. of dry tetrahydrofuran. The reaction is allowed to run overnight with stirring. The dicyclohexylurea which forms during the reaction is filtered. The filter cake is washed with dry tetrahydrofuran. The solution is evaporated to dryness. The solid is taken up in benzene and Washed with sodium bicarbonate solution and then with water and dried over anhydrous sodium sulfate. The solution is concentrated under vacuum to dryness. The p-nitrophenyl-thiaz0lyl-4-carboxylate, is then recrystallized from benzene.

When thiazole-S-carboxylic acid is used in place of its isomer, the isomeric ester is obtained.

B. METHYL 1(4-THIAZOLYL CARBONYL 2METHYL- 5-METHOXY-3-INDOLYLACE'IATE In a 250 ml. round flask (flame dried equipment) is placed at 0 C. with nitrogen, 100 ml. of dry dimethylformamide with 10.5 g. of methyl a-(Z-rnethyl-S-methoxy- 3-indolyl) acetate. To this is added 2.5 g. of 50% sodium hydride mineral oil mixture. After the mixture is stirred for 30 minutes there is added over 15 minutes a solution of 12.5 g. of pnitrophenyl-thiazolyl-4-carboxylate in 50 ml. dry dimethylformamide. The reaction mixture stirred for 4 hours at 0 C. under nitrogen followed by stirring under nitrogen at room temperature overnight. The reaction mixture is then poured into an ice-water ether solution containing a few ml. of acetic acid and the layers are separated. The aqueous phase is washed with ether and the ether extracts are combined and dried over sodium sulfate. To the ether solution is added a saturated solution of hydrogen chloride gas in dry ether. The ether is decanted off, leaving a heavy oil. The oil is washed with ether followed by an addition of aqueous sodium bicarbonate solution. The product is then ex tracted with ether. The ether layer is dried over anhydrous sodium sulfate and concentrated to dryness. The product, methyl l- (thiazolyl-4-carbonyl) -2-methyl-5-methoxy-3-indolyl]acetate is crystallized from benzene and Skellysolve B, MP. 76-82.

EXAMPLE 4 Methyl[1 (2 benzyl 5 chloro 4 oxazolyl carbonyl -2-methyl-5-meth0xy-3-ind0 ly l] acetate On cooling the acid The procedure of Example 3 if followed using 2-benzyl- S-chloro oxazole 4-carboxylic acid in place of thiazole-4- carboxylic acid in Part A and the product of thereof in the procedure of Part B, to yield methyl[1-(2-benzyl-5- chloro 4 oxazolylcarbonyl)2 methyl 5 methoxy- 3-indolyl1acetic acid.

Similarly, when 2-oxazole carboxylic acid,

S-phenyl oxazole-2-carboxylic acid, 2,5-dimethyloxazole-4-carboxylic acid, 2-benzyl-S-ethoxyoxazole-4-carboxylic acid, 2-pheny1-S-methoxyoxazole-4-carboxylic acid,

2-methyl-5-trifiuoromethyloxazole-4-carboxylic acid,

2-benzyl-4-cyano-oxazole-S-carboxylic acid,

2-benzyl-4-thiocarbanoyloxazole-5carboxylic acid, 1-benzylimidazole-2-carboxylic acid,

Z-methylthio-S-methylimidazole-l-carboxylic acid,

Z-iodo,

'y methylimidazole-4-carboxylic acid (prepared by methylation of 2-isdoimidazole-4-carboxylic acid with methyl iodide followed by saponification of the resultant ester with cold dilute caustic),

S-bromo-l-methylimidazole 4-carboxylic acid (similarly prepared by methylation of -bromoimidazole-4-carboxylic acid),

5-cyanomethyl-l,2-dimethylimidazole-4-carboxylic acid (also prepared by methylation of the 1-unsubstituted acid),

1-benzoyl-5-bromoimidazole-4-carboxylic acid,

1-methyl-5-nitroimidazole-4-carboxylic acid (also prepared by CH I methylation of the l-unsubstituted acid),

1,4-dimethyl-2-ethylmercapto-imidazole-S-carboxylic acid (also prepared by CH I methylation of the l-unsubstituted acid),

S-bromo-4-methylthiazole-2-carboxylic acid,

2-alylthiothiazole-4-carboxylic acid,

2-bromoacetylthiazolel-carboxylic acid, 2-(l-hydroxyethyl)thiazole-4-carboxylic acid,

5-phthalimido thiazole-Z-carboxylic acid,

2-chlorallylthio-4-methyl-thiazole-5-carboxylic acid,

2'p-nitrophenylthiazole-5-carooxylic acid,

4-methyl-2-morpholinothio-thiazole-5-carboxylic acid,

2-dimethylaminoethylthio-4-methylthiazole 5-carboxylic acid,

S-methyl-1,2,3-oxadiazole4-carboxylic acid,

isothiazole-4-carboxylic acid,

3-methylthioisothiazole-S-carboxylic acid, 3-methyl-5-acetarnidoisothiazole-4-carboxylic acid, 3ap-chlorophenyl-5-methylisoxazole-4-carboxylic acid, 1,2,3,-thiadiazole-4-carboxylic acid,

S-phenyl-1,2,3-thiadiazole-4-carboxylic acid,

1-phenylpyrazole-3-carboxylic acid,

1-methyl-3-acetylpyrazole-5'carboxylic acid,

1,3,S-trimethylpyrazole-4-carboxylic acid,

1-phenyl-4-bromopyrazole-S-carboxylic acid, and

3,5-dimethylpyrazole-l-carboxylic acid are used in place of thiazole-4-carboxy-lic acid. The corresponding 1-acyl-3-indolyl acid esters are obtained.

EXAMPLE 5 1-(thiazolyl-5-carbonyl) -2-methyl-5-methoxy-3- indolyl acetic acid A. 2-METHYL-5-METHOXY-3-INDOLYLACETIC A-NHYDRIDE Dicyclohexylcarbiimide g., 0.049 mole) is dissolved in a solution of 2-methyl-5-methoxy-3-indolylacetic acid (22 g., 0.10 mole) in 200 ml. of THF, and the solution is allowed to stand at room temperature for 2 hours. The precipitated urea is removed by filtration, and the filtrate is evaporated in vacuo to a residue and flushed with Skellysolve B. The residual oily anhydride is used without purification in the next step.

13. t-BUTYL 2-METHYL-5-METHOXY-3- INDOLYLACETATE t-Butyl alcohol (25 ml.) and fused zinc chloride (0.3 g.) are added to the anhydride from part A. The solution is refluxed for 16 hours and excess alcohol is removed in vacuo. The residue is dissolved in ether, washed several times with saturated bicarbonate, water, and saturated salt solution. After drying over magnesium sulfate, the solution is treated with charcoal, evaporated, and flushed several times with Skellysolve B for complete removal of alcohol. The residual oily ester (18 -g., 93%) is used without purification.

A stirred solution of ester (18 g., 0.065 mole) in dry dimethylformamide (450 m1.) is cooled to 4 in an ice bath, and sodium hydride (4.9 g., 0.098 mole, 50% susp.) is added in portions. After 15 minutes, p-nitrophenylthiazole-S-carboxylate (prepared in Example 3A) (0.085 mole) in dimethylformamide is added dropwise during 10 minutes, and the mixture is stirred for 4 hours at 0 C. under nitrogen followed by overnight at room temperature. The mixture is then poured into an ice water ether mixture containing a few ml. of acetic acid. The layers are separated and the aqueous phase is extracted with ether. The ether solutions are combined, dried over sodium sulfate, and to the solution is added a saturated solution of dry H0 in ether. The ether is decanted, leaving a heavy oil which is washed with water followed by aqueous NaHCO solution. The product is then extracted with ether and the extract is dried over anhydrous Na HSO Evaporation of the ether yields t-butyl l-(thiazolyl-S-carbonyl)-2-methyl-5-methoxy-3-indolyl acetate which is purified by chromatography on a column of neutral alumina using ether-petroleum ether (v./v. 2060%) as the eluant.

D. 1- THIAZOLE-5CARBONYL) -2-METHYL-5-METHOXY- 3-INDOLYLACETIC ACID A mixture of 1 g. of the preparation in Part C and 0.1 g. powdered porous plate is heated in an oil bath at 210 with magnetic stirring under a blanket of nitrogen for about 2 hours. No intensification of color (pale yellow) occurs during this period. After cooling under nitrogen, the product is partitioned between a mixture of ether and dilute ammonium carbonate. The aqueous solution is filtered with suction to remove ether, neutralized with acetic acid, and diluted with ethanol to precipitate the zwitter ion. The crude product 1-(thiazol-5-carbonyl)- 2-methyl-S-methoxy-S-indolyl acetic acid is recrystallized from aqueous ethanol and dried in vacuo.

EXAMPLE 6 Ethyl 2-[1-(0xaz0le-4-carb0xyl)-2-methyl 5-meth0xy-3- indo lyl] propionate The procedure of Example 3A is followed, using oxazole-4-carboxylic acid instead of .thiazole-4-carboxylic acid to produce p-nitrophenyl 4-oxazolyl carboxylate. This is then used in the procedure of Example 3B, using ethyl 2- (Z-methyl-S-methoxy-B-indolyl) propionate instead of methyl 2-methyl-5-methoxy-3-indolyl acetate, to produce ethyl 2-[ 1- oxazolyl-S-carboxy) -2-methyl-5methoxy-3-indolyl] propionate.

EXAMPLE 7 1 (J-methylimidazolyI-Z-carbonyl) -2-methyl-5- metlz0xy-3-ind0lyl-acetic acid A. A solution of 15 g. of methyl (Z-methyl-S-methoxy- 3-indolyl)-acetate and 0.2 g. of sodium in 60 ml. of benzyl alcohol is slowly fractionated over a period of 4 /2 hours through a Vigreux column to remove methanol. The excess benzyl alcohol is then removed by distillation at 60 C. (2.5 mm.) to give a residue of 18.6 g. of benzyl- (Z-methyl-5-methoxy-3-indolyl -acetate.

B. 10 g. of the benzyl ester obtained above is added to 6.6 g. of 51% sodium hydride-mineral oil emulsion in 260 ml. of dimethylformamide according to the procedure of Example 2. This mixture is treated as described in that example with 1-methylimidazolyl-2-carboxy chloride (prepared by heating the free acid with SOC1 followed -by removal of the excess SOC1 in vacuo) and the reaction mixture worked up by the above-described process using a chromatographic column of 340 g. of alumina and eluting with 20-30% ether in petroleum ether. From these eluates there is obtained benzyl [1-(1-methylimidazolyl-Z-carbonyl)-2-methyl-5-methoxy 3 indolyl].- acetate.

C. 1.5 g. of the ester obtained in Part B above is added to 20 ml. of ethyl acetate containing a drop of acetic acid and reduced catalytically at room temperature in the presence of palladium on charcoal catalyst. When the reduction is complete the catalyst is removed by filtration and the filtrate evaporated to a crystalline residue. This residue is recrystallized from aqueous ethanol to give 1-(1- methylimidazolyl-Z-carbonyl)-2-methyl-5-methoxy 3-indolyl acetic acid.

EXAMPLE 8 1- (2-phenyl-4-methyloxazolyZ-S-carbonyl) -2-methyl- -methoxy-3-ind0lyl acetic acid The procedure of Example 5 is followed, using Z-phenyl-4-methyloxazole-S-carboxylic acid in place of thiazole- S-carboxylic acid to produce 1-(2-phenyl-4-methyloxazolyl 5 carbonyl)-2-methy1-5-methoxy S-indolyl acetic acid. Similarly, when any of the fol-lowing acids are used in equivalent quantities in place of thiazole-S-carboxylic acid, the corresponding 1-acyl-2-methyl-3-indolyl acetic acid is formed:

2-phenyl-5-hydroxymethyloxazole-4-carboxylic acid 4-methyloxazole-S-carboxylic acid 2-phenyl-4-methyloxazole-S-carboxylic acid 1-phenylimidazole-2-canboxylic acid 1-methyl-2-phenylimidazole 4-carboxylic acid 1-benzoyl-4-methylimidazole-S-carboxylic acid 1-ethoxymethyl-4-(or 5)imidazole carboxylic acid 4,5-dimethylthiazole-2-carboxylic acid 5-chlorothiazole-Z-carboxylic acid 5-bromothiazolea2-carboxylic acid 5-thalimidothiazole-2-carboxylic acid 2-bromothiazole-4-carboxylic acid 2-chlorothiazole-4-carboxylic acid 3-acetylthiazole-4-carboxylic acid 2-bromothiazole-S-carboxylic acid 2-ohloro-4-methylthiazole-5-carboxylic acid 4-methyl-2- (p-methylsulfonylphenyl) thiazole S-canboxylic acid EXAMPLE 9 2-(methylthi0-4-methylthiazolyl-5-carbonyl)-2-methyl- 5-methoxy-3-ind0lyl-a-pr0pi0nic acid A. 2-METHYL-5-METHOXY-3-INDOLYL-a-PROPIONIC ANHYDRIDE Dicyclohexylcarbodiimide '(9 g., 0.044 mole) is dissolved in a solution of 2-methyl-5-methoxy-3indolyl-apropionic acid (21 g., 0.09 mole) and 200 ml. of TH F, and the solution is allowed to stand at room temperature for two hours. The precipitated urea is removed by filtration, and the filtrate is evaporated in vacuo to a residue and flushed with Skellysolve B. The residual oily anhydride is used without purification.

B. t-BUTYL Z-METHYL-5-METHOXY-3-I NDOLYL- a-PROPIONATE t-Butyl alcohol (25 ml.) and fused zinc chloride (0.3

g.) are added to the above anhydride. The solution is refluxed for 16 hours, and excess alcohol is removed in vacuo. The residue is dissolved in ether, washed several times with saturated bicarbonate, water and saturated salt solution. After drying over magnesium sulfate the solution is treated with charcoal, evaporated, and flushed several times with Skellysolve B for complete removal of alcohol. The residual oil ester (14 g.) is used without purification.

C. 't-BUTYL 1-(2 METHYLTHIO-l-METHYLTHIAZOLYL- 5-CARBONYL) 2 METHYL-5-METHOXY-S-LNDOLYL-a- PROPIONATE A stirred solution of ester from part B (20 g., 0.69

mole) in 450 ml. of dry dimethylformamide is cooled to 4 in an ice bath and sodium hydride (5.2 g., 0.10 mole,

50% susp.) is added in portions. After the mixture is stirred for ten minutes, a DM-F solution of Z-methylthio- 12 4-methyl thiazole-S-carboxy chloride (0.091 mole) prepared by heating the acid with SOCl followed by evaporation in vacuo is added in portions during ten minutes, and the mixture is stirred for seven hours at room temperature without replenishing the ice bath. The mixture is then poured into 1.1 of 5% acetic acid, extracted with ether, washed thoroughly with water, bicarbonate, saturated salt solution, dried over magnesium sulfate, treated with charcoal, and evaporated in vacuo to a residue. This is dissolved in ether, mixed with g. of acid washed alumina, and evaporated in vacuo to dryness. The residue is placed above a column of 300 g. of neutral alumina in Skellysolve B. After washing with Skellysolve B, the

product is eluted with 5% ether-Skellysolve B.

D. l-(2-METHYL'IHIO 4 METHYLTHIAZOLYLQ-CAR- BONYL)-2-METHYL 5 METHOXY-3-INDOLYL-a-PRO- PIONIC ACID The pyrolysis is carried out in the same manner as with t-butyl 1 (thiazolyl-S-carbonyl)-2-methyl-5-methoxy-3- indolyl acetate (of Example 51)). The product is recrystallized from aqueous ethanol or benzene-Skellysolve B.

EXAMPLE l0 Methyl (2-methyl-5-nitr0-3-ind0lyl) acetate A solution of 40 g. of levulinic acid in 300 ml. of hot Water is added to a solution of 65 g. of p-nitrophenylhydrazine hydrochloride in 700 ml. of hot Water with stirring. After about one-half hour, the hydrazone derivative is collected in a filter, washed with water and dried at in vacuo. The yield is '84 g., -M. P. 175-179".

An amount of 42 g. of the above hydrazone is added to a solution of g. of fused zinc chloride, in 100 ml. of absolute ethanol and the mixture is refluxed for 18 hours. The cooled solution is poured into dilute hydrochloric acid with stirring, and the insoluble gummy material separated is extracted with hot ethanol. The ethanolic extract is evaporated in vacuo to a syrup, which is redissolved in ether. The ether solution is extracted with 10% sodium carbonate several times. Acidification of the aqueous solution gave a crude produce which recrystallizes from chloroform to give (2-methyl-5-nitro-3-indolyl) acetic acid, M:P. 238.

The above acid is treated with a mixture of 3 g. of sulfuric acid and 4 0 ml. of methanol at the reflux temperature for 6 hours. The methyl ester is obtained as a yellow crystalline product, -M.P. 132-40 after recrystallization from benzene.

Similarly, methyl a(2-methyl-5-nitro-3-indolyl)-propionate is prepared by using an equivalent amount of 0!.- methyl levulinic acid as the starting material.

EXAMPLE 11 Methyl (2-methyl-5-amin03-ind0lyl) acetate 3 g. of methyl (2-methyl-5-nitro-3-indolyl) acetate is dissolved in 300 ml. dry methanol and reduced in hydrogen in an autoclave with Raney nickel as catalyst. After the theoretical amount of hydrogen is taken up the catalyst is removed by filtration. The catalyst and reaction flask are washed with methanol. The methanol solution is evaporated to dryness. The product is crystallized from benzene, M.P. .1441 45.

Micr0analysiS.Calc.t C, 66.03; H, 6.47; N, 12.84. Found: C, 65.96; H, 6.29; N, 12.56.

EXAMPLE 12 Methyl[Z-methyl-S-(1'-pyrr0lidin0 -3-ind0lyl] acetate In a ml. flask is placed '80 ml. of ethanol. To this is added 1.0 g. of methyl (2-methyl-5-amino-3-indolyl) acetate, 0.99 g. of 1,4-dibromobutane and 0.975 g. of anhydrous sodium carbonate. This mixture is -stirred at refiux temperature in a nitrogen atmosphere for 6 hours. The reaction mixture is then filtered and the filtrate is concentrated in vacuo to a small volume and diluted with ether. This solution is then washed with water 2X, dried with anhydrous sodium sulfate and concentrated in vacuo to dryness. The product is absorbed on 6 g. of silica gel. The product is then chromatographed over 30 g. of silica gel using as eluant from v./v. 3:1 ether-petroleum ether to ether. The eluted material is combined and crystallized from benzene-Skellysolve B. MP. 11711 8.

Microanalysis.Calc.: C, 70.56; H, 7.40; .N, 10.29. Found: C, 70.77; H, 7.72; N, 10.00.

When ethylene dibromide is used instead of dibromo butane, the product obtained is the 5-(1-azacyclopropyl) indolyl compound.

EXAMPLE 13 Methyl [1(thiazolyl-4-carbonyl -2-methyl-5- (1 pyrrolidino)-3ind0lyl] acetate The procedure of Example 3B is followed using methyl [2-methyl-5-( l'-pyrrolidino)-3-indolyl] acetate in place of the indole ester from 3A used in that example, to produce methyl [1 (thiazolyl-4-carbonyl)-2-methyl-5 (1-pyrrolidino)-3-indolyl] acetate.

EXAMPLE 14 Methyl [1'0xaz0lyl-4-carb0nyZ-2-methyl-5-nitro-3-indolyl] acetate In a dried 250 ml. flask is placed 3.9 g. of methyl (2- methyl-5-nitro-3-indolyl) acetate in 125 ml. dry dirnethylformamide. To this solution cooled to C. is added 0.8 g. of 50% sodium hydride-mineral oil. This is stirred under nitrogen for 30 minutes. To this is added dropwise 4.0 g. of p-nitrophenyl-oxazole-4-carboxylate (prepared as in Example 3A) in 15 ml. of dry dimethylformamide over a -minute period. The reaction mixture is stirred 4 hours at 0 C. under nitrogen. It is then poured into an ice-Water-ether solution containing a few milliliters of acetic acid. The ether layer is separated and the aqueous layer is washed with ether. To the combined ether layers after drying over Na SO is added a saturated solution of hydrogen chloride gas in dry ether. The ether layer is decanted and the residue is washed with ether followed by an addition of aqueous NaHCO solution. The alkaline solution is then extracted with ether and the ether layer is dried and evaporated in vacuo. The product, methyl [1 oxazoylyl 4-carbonyl)-2-methyl-5-nitro-3-indolyl] acetate is crystallized from dry ether and Skellysolve B.

EXAMPLE 15 Methyl [1-(0xaz0lyl-4-carb0nyl)-2-methyl-5-dimethylamin0-3-ind0lyl] acetate To a solution of 0.387 g. of methyl a-[l-(oxazolyl-4- carbonyl)-2-methyl-5-nitro-3-indolyl] acetate in 20 ml. of distilled dimethoxyethane is added 1.5 ml. of glacial acetic acid and 0.5 ml. of a 37% solution of aqueous formaldehyde. This mixture is reduced with Raney nickel at 40 p.s.i. and room temperature. After the theoretical amount of hydrogen has reacted, the reaction mixture is filtered, concentrated in vacuo to a small volume and diluted with ether. The ether solution is washed with sodium bicarbonate, then with water, dried with anhydrous sodium sulfate and concentrated in vacuo. The residue is chromatographed on 30 g. of neutral alumina using ether-pet, ether (v./v. 30-l00%) as eluant.

EXAMPLE 16 Methyl [1- (oxaz0lyl-4-carb0nyl) -2-methyl-5-acetamin0- 3-ind0lyl] acetate To 0.388 g. of methyl [1-(oxazolyl-4-carbonyl)-2-methyl-5-nitro-3-indolyl] acetate in 30 ml. of anhydrous ethyl acetate is added 0.306 g. acetic anhydride. The mixture is reduced with Raney nickel at room temperature and 40 p.s.i. After the theoretical amount of hydrogen has been absorbed, the catalyst is removed by filtration. The solution is concentrated in vacuo to a small volume and poured into an ice-water-ether mixture. The ether layer is sep- Benzyl (2-methyl-5-nitr0-3-indolyl) acetate In a dry 250 ml. flask is placed ml. dry benzene and 20 ml. benzyl alcohol. To this is added 3.0 g. of 2-methyl- 5-nitro-3-indolyl acetic acid and 0.2 g. of p-toluenesulfonic acid. This slurry (which clears on heating) is heated to reflux under nitrogen. The water formed during the reaction is collected in a Stark and Dean tube. The reaction is stopped when the distillate is clear (about 2 hours). The excess benzyl alcohol is removed in vacuo. and washed with sodium bicarbonate followed by water, dried over anhydrous magnesium sulfate and concentrated in vacuo. The product is absorbed on 16 g. of acid Washed alumina and chromatographed over 75 got acid washed alumina. The product is eluted with v./v. 1:1-3 :1 etherbenzene. The eluate is evaporated and the combined product is crystallized from benzene-Skellysolve B, M.P. 147-148".

Micr0analysis.Calc.: C, 66.66; H, 4.97; N, 8.64. Found: C, 66.83; H, 4.77; N, 8.52.

EXAMPLE 18 Benzyl (1-0xaz0Zyl-4-carb0nyl-2-methyl-5-nitr0-3-ind0lyl) acetate In a dry 125 ml. flask is placed 3.0 g. of benzyl (2- methyl-5-nitro-3-indolyl) acetate in 60 ml. of dry dimethylformamide. To this solution, cooled to 0 C. in a nitrogen atmosphere is added 0.475 g. of 50% sodium hydride-mineral oil. This is stirred for 30 minutes. Then 2.32 g. of p-nitrophenyl oxazole-4-carboxylate in 10 ml. of dry dimethylformamide is added dropwise over a 5 minute period. The reaction mixture is stirred at 0 C. for 4 hours under a nitrogen atmosphere followed by stirring at room temperature under nitrogen overnight. It is then poured into an ice water-ether mixture. The ether layer is separated and the aqueous layer is washed with ether. The combined ether extracts are acidified with an ether solution of dry HCl and the ether is decanted. The residue is washed with ether and then stirred with aqueous NaHCO solution. The alkaline mixture is extracted with ether and the extracts are dried with anhydrous sodium sulfate and concentrated in vacuo to dryness. The product, benzyl [1-(oxazolyl-4-carbonyl)-2- methyl-5-nitro-3-indolyl] acetate, is crystallized from benzene-Skellysolve B.

EXAMPLE 19 Methyl ot- [1 (oxazoly l-4-carb0nyl -2-mefhyl-5-amin0-3- indolyl] propionate 0.025 M of methyl w[l-(oxazolyl-4-carbonyl)-2-methyl-S-nitro-S-indolyl] propionate in ml. of ethanol is hydrogenated in the presence of mg. of 10% palladium or charcoal catalyst at 40 p.s.i. at room temperature. After 0.075 M of hydrogen has been consumed, the hydrogenation is stopped, and the solution filtered to remove the catalyst. The filtrate is concentrated to dryness in vacuo to give methyl u-[1-(oxazole-4-carbonyl)-2-methyl-5-amino-3-indolyl] propionate.

EXAMPLE 20 Methyl [1-(Z-hydroxyimidaz0lyl-5-carb0nyl) -2-methyl- 5 -meth0xy-3-ind0lyl acetate] A. p NITROPHENYL-l-BENZYL-2-BENZYLOXYIMIDAZ- OLE fi-CARB OXYLATE To a solution of l-benzyl-2hydro.xyimidazole-S-carboxylic acid (0.1 mole) in 200 ml. of dry dimethylform- The residue is dissolved in benzene 1 5 amide under nitrogen is added 0.2 mode sodium hydride in 50% mixture with mineral oil. The mixture is stirred 30 minutes at room temperature and then 0.22 mole of benzyl chloride is added over 15 minutes. The mixture is stirred four hours at C. under nitrogen and then at room temperature for 18 hours. The crude product is saponified at room temperature with 0.2 N sodium hydroxide in 90% aqueous ethanol to give 1-benzyl-2-benzyloxyimidazole-S-carboxylic acid. The procedure of Example 3A is followed using 1-benzyl-2-benzyloxyimidazole-S-carboxylic acid in place of thiazole-4-carboxylic acid to produce p-nitrophenyl-1-benzyl-2-benzyloxyimidazole-S-carboxylate.

B. METHYL [1-(1 BENZYL-2-BENZYLOXYIMIDAZOLYL- 2-CARBONYL)-2-METI-IYL 5 METHOXY-3JNDOLYL] ACETATE The procedure of Example 3B is followed using pnitrophenyl-1-benzyl-2-benzyloxyimidazole 5 carboxylate in place of the thiazole carboxylate used therein. The product is methyl [1-(1-benzyl-2-benzyloxyimidazolyl-5- carbonyl) -2-methyl-5-methoxy-3-indolyl] acetate.

C. METHYL [1-(2 HYDROXYIMIDAZOLYLfi-CARBON- YL -2-METHYL-5-METHOXY-3-I NDOLYL] ACETATE A solution of 0.1 mole of the product of Part B in 150 'ml. of methanol is shaken with 3 g. of palladium on charcoal and hydrogen until hydrogen uptake ceases. The catalyst is filtered and the filtrate is taken to dryness in vacuo to yield methyl [1-(Z-hydroxyimidazolyl-S-carbonyl)-2-methy1-5-methoxy-3-indolyl] acetate.

D. When the procedures of parts A, B and C are followed, using 2-phenyl-5-hydroxymethyloxazolyl-4-carboxylic acid, 2-(1-hydroxyethyl) thiazole-4-carboxylic acid or Z-hydroxy thiazole-S-carboxylic acid in place of 1-benzyl-2-hydroxyimidazolyl-5-carboxylic acid, the corresponding l-acyl indole compounds are obtained.

EXAMPLE 21 A. Methyl [1- (0xaz0lyl-4-carb0nyl) -2-methyl-5-bis (li-hydroxyethyl) amin0-3-ind0lyl] acetate A mixture of 0.02 mole of methyl a-[1-(oxazolyl-4- carbonyl)-2-methyl-5-amino-3 indolyl]propionate, 0.044 mole of ethylene oxide and 0.03 mole of acetic acid in 300 ml. dimethoxyethane is heated to 100 for 18 hours in an autoclave. The mixture is then diluted with water and filtered to yield crude methyl [1-p-(oxazoly1-4-carbon- -yl)-2-methyl-5-bis(fi hydroxyethyl)amino 3 indolyl]- prop-ionate.

When an equivalent amount of propylene oxide is used -in the above procedure in place of the ethylene oxide, there is obtained methyl [1-(oxazolyl-4-carbonyl)-2- methyl-S-bis(hydroxypropyl)amino 3 indolyl]-propionate.

B. Methyl [1-(0xaz0lyl-carbonyl)-2-methyl-5-(4'- methy l-1 -piperazinyl -3-ind0lyl] acetate The product of A is stirred at 0 in pyridine with two mole proportions of p-toluenesulfonyl chloride until the reaction is substantially complete. The mixture is poured into water and the S-bis(p-toluenesulfonyloxyethyl)amino 1 0 EXAMPLE 22 Methyl [1-(0xaz0lyl-4-carb0nyl)-2-methyl-5-(4'- morpholinyl) -3-ind0lyl]acetate A solution of tosyl chloride (0.1 mole) in 200 ml. benzene is added dropwise with stirring to a solution of methyl a-[1-(oxazolyl-4-carbonyl)-2-methyl-5-bis((3 hydroxyethyl)amino-3-indolyl1acetate (0.1 mole) and pyridine (0.3 mole) in 300 ml. benzene at room temperature over a period of one hour. The mixture is then heated under reflux for three hours, washed with water, dried over sodium sulfate and evaporated to a syrup. Chromatography of the syrup on an alumina column using 3050% (V./v.) ether in petroleum ether as the eluent gives methyl [1-(oxazolyl-4-carbonyl)-2-methyl 5 (4'- morpholinyl -3-indolyl] acetate.

The above product, when used in the procedure of Example 7, gives the corresponding free acid.

EXAMPLE 23 A. Z-methyl-5-cyan0-3-ind0lyl acetic acid methyl ester A solution of p-cyano phenylhydrazine (0.1 mole) and levulinic acid (0.1 mole) in 200 ml. concentrated hydrochloric acid is heated at for 20 minutes and diluted with iced water (400 ml). The crude product which separates is extracted with ether and chromatographed on a silica gel column to give 2-methyl-5-cyano- 3-indolyl acetic acid using 2050% (v./v.) ether and petroleum ether as the eluent.

The methyl ester is prepared by treatment with diazomethane in ether until the yellow of diazomethane persists and the mixture is evaporated.

B. Methyl a-[1-(oxazolyl-4-carb0nyl)-2-methyl-5- cyan0-3-ind0lyl] acetate Acylation of the ester (prepared in Example 23A above) in dimethylformamide with sodium hydride and p-nitrophenyl-oxazole-4-carboxylate, by the procedure of Example 3, gives methyl [l-(oxazolyl-4-carbonyl)-2- methyl-5-cyano-3-ind0lyl] acetate.

C. Methyl a- [1-(0xaz0lyl-4-carb0nyl) -2-methyl-5- amin0methyl-3-ind0lyl] acetate The S-cyano ester prepared in Example 23B is hydrogenated in ethanol in the presence of Raney nickel and 3 moles of anhydrous ammonia at 2000 p.s.i. at room temperature to give, after filtration of the catalyst and evaporation of the reaction mixture, methyl [l-(oxazolyl- 4-carbonyl)-2-methyl-5-aminornethyl 3 indolyl] acetate which can be recrystallized from aqueous ethanol.

D. Methyl [1-(0xaz0lyl-4-carb0nyl) -2-melhyl-5- dimethylaminomethyl-3-ind0lyl] acetate Treatment of the above a-aminomethyl indole with 2 moles of methyl iodide gives the S-dimethylaminoethyl derivative. When ethyliodide is used in place of methyl iodide, the S-diethylaminomethyl derivative is obtained.

B. When the products of Examples 23C and 23D above are used in the procedure of Example 7, the corresponding free acids are obtained.

EXAMPLE 24 a [1- (0xaz0lyl-4-carb0nyl) -2-mezhyl-5-meth0xy- 3-ind0lyl1-butyric acid When the procedure of Examples 1 and 2 are followed using ethyl a-ethyl levulinate in place of ethyl a-methyl levulinate, there is obtained successively ethyl a-(2-methyl-5-methoxy3-indolyl)-butyrate and ethyl d- [1 (oxazolyl 4 carbonyl)-2-methyl-5-methoxy-3-indolylJ-butyrate. When the latter product is used in the procedure of Example 7 the corresponding butyric acid derivative is obtained.

The starting ethyl a-ethyl levulinate is prepared by alkylation of the sodi-o derivative of ethyl acetoacetate in ethanol with 1 m. of ethyl a-bromobutyrate, followed by hydrolysis and decarboxylation. The a-ethyl levulinic acid obtained is reesterified with 2 N ethanolic hydrogen chloride at refiux temperature for 18 hours.

EXAMPLE 25 6.5 g. (0.02 mole) of ot-[l-(oxazolyl-4-carbonyl)-2- methyl--methoxy-3-indolyl]-acetic acid, is added to 50 ml. of water which has been flushed with nitrogen. The slurry is stirred under nitrogen and ml. of 1.05 N sodium carbonate added with stirring. When a clear solution is obtained, a solution of 2.2 g. of

in 8 ml. of water is added with vigorous stirring. The mixture is stirred until it is homogenous and the solid aluminum salt of [1-(oxazolyl-Z-carbonyl)-2-methyl-5- methoxy-3-indolyl1acetic acid, is recovered by filtration and washed with water and with ethanol.

In a similar fashion, there may be prepared the sodium and aluminum salts as well as other salts, such as the potassium, iron and magnesium salts, of the various (3-indolyl) aliphatic acids described in the accompanying examples.

EXAMPLE 26 The procedure of Example 5A is followed using [1 (oxazolyl 4 carbonyl)-2-methyl-5-methoxy-3-indolyl] acetic acid in place of the l-unsubstituted acid. The product, 1 (oxazolyl 4 carbonyl) 2-methyl-5- methoxy-3-indolyl acetic anhyride, is found on testing to be about equal to the free acid in the allevation of inflammation.

When any of the other l-substituted free indolyl acids herein described are used in the procedure of Example 5A, the corresponding anhydride is obtained.

EXAMPLE 27 The procedure of Example 1A is followed using an equivalent quantity of p-ethoxyphenylhydrazine hydrochloride in place of the methoxyphenylhydrazine to give ethyl or (2 methyl 5 ethoxy 3 indolyl)propionate. When this is used in the procedure of Example 3 there is obtained ethyl or [1 (oxazolyl 4-carbonyl)-2-rnethy1- 5-methoxy-3-indolyl] propionate. This product, when used in the procedure of Example 7, yields the corresponding free ct-indolyl propionic acid.

Similarly when p-propoxy, p-butoxy, p-benzyloxy, p- 4-methylbenzyloxy, p-4-methoxy-benzyloxy, p-4-chlorobenzyloxy phenylhydrazine are used in the above procedures, the correspondingly 5-substituted indolyl acids are obtained. When the l-(oxazolyl-4-carbonyl)-2- methyl S-benzyloxy- (or substituted benzyloxy) 3-indolyl propionic acids so prepared are subjected to catalytic hydrogenation over palladium, there is obtained OL-[l- (oxazolyl 4 carbonyl)-benzyl-2-methyl-5-hydroxy-3-indolyl]propionic acid.

When the procedure of Example 1A is followed using in place of the p-methoxyphenylhydrazine, equivalent amounts of p -ethylphenylhydrazine, p-butylphenylhydrazine, p-trifiuoromethylphenylhydrazine, p-chlorophenylhydrazine and p-fluorophenylhydrazine (each obtainable by diazotization of the corresponding p-substituted aniline and reduction of the diazo) and the resultant indolyl ester is acylated by the procedure of Example 3 and further treated by the procedure of Example 7, the corresponding 5-suhstituted indolyl esters and acids are obtained.

When the procedure of Examples 1A, 3 and 7 are followed starting with phenylhydrazine, the corresponding S-unsubstituted indolyl esters and acid are produced.

18 EXAMPLE 2s (Oxaz0lyl-4-carb0nyl) -2-methyl-5-meth0xy-3 indolyl acetamide To a suspension of 1.0 g. of 50% sodium hydride in ml. benzene is added 4.4 g. of 2-methyl-5-methoxy- 3-indolylacetamide with stirring. Twenty ml. of dinuethylformamide is then added, followed by 2.8 g. oxazole-4-carbonyl chloride twenty minutes later. The reaction mixture is stirred at room temperature for one hour and then poured into 400 ml. of ice and water. The crude product is extracted with ether, dried over sodium sulfate and evaporated to a residue. The residue is chromatographed on a column of 300 g. silica gel using ether-ethyl acetate mixture as eluent.

EXAMPLE 29 I oxazolyl l-carbo'nyl -2-mezhyl-5-methoxy-3- indolyl acetic acid To a solution of 3.2 g. of 1-(oxazolyl-4-ca-rbonyl)-2- methyl 5 methoxy 3-indolylacetamide in 50 m1. dimethoxyethane containing 1 ml. of l2 N hydrochloric acid at 0 is added 0.7 g. of sodium nitrite with stirring. After gas evolution has subsided the mixture is neutralized with dilute ammonium by dioxide concentrated in vacuo and then diluted with ethanol to precipitate the product which is purified by recrystallization aqueous ethanol.

EXAMPLE 30 The procedure of Example 1A is followed using an equivalent quantity of each of the following phenylhydrazines in place of the p-methoxyphenyl hydrazines; pdimethylsulfonamidophenylhydrazine, p-benzylmercaptophenylhydrazine.

When the resulting indolyl acid is acylated by the procedure of Example 3, the corresponding l-(thiazolyl-4 carbonyl)indolyl acids are obtained.

EXAMPLE 31 Methyl 1-(thiazo lyll-carbonyl) -2-meZhyl-5-allyl0xy- S-indolyl acetate A. METHYL 5-HYDROXY 2-ME1HYL-3 INDOLYL ACETATE A mixture of 10 g. of methyl 5-methoxy-2-methyl-3- indolyl-acetate and 50 g. of pyridine hydrochloride is heated at 180 under nitrogen for 15 minutes. The reaction mixture is then cooled to about 50, dissolved in ml. of 1.5 N methanolic hydrogen chloride and refluxed for 2 hours. After cooling, the solution is concentrated in vacuo, poured into water and extracted with ether. The ethereal solution is Washed with water and extracted three times with 50 ml. of 5% sodium hydroxide. The combined aqueous extract is acidified to pH 6 and extracted with ether. After drying over sodium sulfate, the ethereal solution is evaporated to give methyl 5-hydroxy-2-methyl-3-indoly1 acetate, recrystallized from benzene, MP. 158 (3.4 g.).

B. METHYL 2 METHYL-5-ALLYLOXY3 INDOLYL ACETATE A mixture of 3.4 g. of the S-hydroxy-indole, 2.4 g. of allylbromide and 7.5 g. of potassium carbonate is stirred at room temperature to 56 for 18 to 6 hours. The reaction mixture is filtered, concentrated in vacuo to a syrup and chromatographed on 60 g. of silica gel, using v./v. 50% ether in petroleum ether as: eluent to give 0.7 g. of methyl 5-allyloxy-2-methyl-3-indolyl acetate as an oil.

0. 1-(TI-IIAZOLYL-4-CARBONYL)-2METHYL-5-ALLYL- 0XY-3-INDOLYL ACETATE The procedure of Example 3 is followed, using the above 5-allyloxy compound in place of the 5-methoxy compound to give methyl-l-(p-chlorobenzoyLZ-methyl- 19 5-allyloxy-3-indolyl) acetate, recrystallized from benzene- Skellysolve B.

Similarly when allyl bromide is replaced by an equivalent amount of cyclopropylmethyl bromide, cyclobutylmethyl bromide, and isopropyl bromide, the corresponding 5-cyclopropylmethoxy, 5-cyclobutylmethoxy, S-isopropoxy-analogs are obtained.

EXAMPLE 32 3-trifluor melhylphenylhydrazine 250 mls. of chilled concentrated hydrochloric acid is slowly added with stirring, to 0.40 of a mole of freshly distilled 3-aminobenzotrifluoride, which is kept cooled in an ice salt bath. When the temperature of the above suspension is 0, a precooled solution of 0.40 of a mole of sodium nitrite in 125 mls. of water is added through a separating funnel, whose tip is immersed below the surface of the suspension. The addition is carried out over 75 minutes, maintaining the reaction below 3. A chilled solution of 0.89 moles of stannous chloride dihydrate in 200 mls. of concentrated hydrochloric acid is then added dropwise to this stirred and cooled diazonium solution, over a period of three hours. During this addition, the temperature is maintained at 05 and after the addition, the solution is stirred for an additional hour at 0. The resulting solid is collected by filtration, pressed as dry as possible and then shaken with 700 mls. of 25% sodium hydroxide. The yellow mixture obtained is allowed to stand overnight at room temperature. The mixture is then extracted with three 300 ml. portions of benzene. The combined filtered benzene solution is dried over 20-30 gms. of potassium hydroxide. Distillation, under vacuum, of this benzene solution gives 3-trifluoromethylphenylhydrazine.

When equivalent amounts of Z-aminobenzotrifiuoride, 4 methoxy 3 trifiuoromethylaniline, 4-methoxy-2-trifluoromethylaniline, 4-butoXy-3-trifiuoromethylaniline, 4- methyl-Z-trifiuoromethylaniline, or 4-methyl-3-trifluoromethylaniline is employed in the above procedure in place of 3-aminobenzotrifluoride, there is obtained Z-trifluoromethylphenylhydrazine, 4 methoxy 3 trifluoromethylphenylhydrazine, 4 methoxy-Z-trifluoromethylhydrazinc, 4-butoxy-3-trilluoromethylphenylhydrazine, 4 methyl-2- trifluoromethylphenylhydrazine, or 4-methyl-3-trifluoromethylphenylhydrazine, respectively.

EXAMPLE 33 Methyl 4- and 6-triflu0r0methyl-3-ind0lylacetate 0.2 mole of methyl 'y,'y-dimethoxybutyrate is added, dropwise with stirring, to a solution of 0.2 mole of 3- trifluoromethylphenylhydrazine in 75 ml. of 50% acetic acid. The mixture is allowed to stir at room temperature for three hours, and then 300 ml. of water is added. The crude hydrazone which separates out is collected and dried in vacuo. 0.04 mole of the dried hydrazone is then intimately mixed With 0.85 mole of freshly fused zinc chloride. To this mixture is added, with stirring, for 5 minutes at room temperature, 135 ml. of glacial arctic acid and 5 ml. acetic anhydride. The mixture is then refluxed for one hour and cooled to room temperature. This resulting mixture is poured onto chopped ice and water and allowed to stand overnight in a refrigerator. The solid is collected and precipitated by filtration and chromatographed on acid-washed alumina and eluted with ether-petroleum ether (v./v. S-50%). The two isomers which are obtained, namely, methyl (4-trifluoromethyl- 3-indolyl) acetate and methyl (6-trifluoromethyl-3-indolyl) acetate are differentiated by nuclear magnetic resonance spectroscopy.

When equivalent amounts of 4-methoxy-3-trifluoromethylphenylhydrazine, 4 butoxy-3-trifluoromethylphenylhydrazine, or 4 methyl-3-trifluoromethylphenylhydrazine is employed in the above procedure in place of 3- trifluoromethylphenylhydrazine, there is obtained both isomers of each, namely,

methyl (5-methoxy-4-trifiuoromethyl-3-indolyl) acetate, methyl (5-methoxy-6-trifluoromethyl-3-indolyl) acetate; methyl (5-butoxy-4-trifiuoromethyl-3-indolyl) acetate; methyl (5-butoxy-6-trifiuoromethyl-3-indolyl) acetate; or methyl (5-methyl-4-trifluoromethyl-3-indolyl) acetate; methyl (5-rnethyl-6-trlfluoromethyl-3-indolyl) acetate,

respectively.

Similarly, when equivalent amount of 2-trifluoromethylphenylhydrazine, 4-methoxy-Z-trifluorometbyl hydrazine, or 4-methyl-2-trifluoromethylphenylhydrazine is employed in place of 3-trifluoromethylphenylhydrazine, there is obtained methyl (7-trifluoromethyl-3-indolyl) acetate; methyl (5-methoxy-7-trifluoromethyl-3-indolyl) acetate; or methyl (5-methyl-7-trifluoromethyl-3-indolyl) acetate, respectively.

EXAMPLE 34 Methyl a- [4 0r 6 -tri fluor0me1hyl-3 -ind0lyl propionafe When the procedure of Example 40 is followed, using methyl-'y,'ydimethoxy-a-rnet'hyl-butyrate in place of methyl-'y,' -dimethoxybutyrate, there are obtained two isomers, namely, methyl-u-(4-trifluoromethyl-3-indolyl) propionate and methyl-a-(6-trifluoromethyl-S-indolyl) propionate.

When equivalent amounts of 4-methoxy-3-trifluoromethylpr'tenylhydrazine, 4 butoxy 3 trifluoromethylphenylhydrazine, or 4-methyl-3-trifluoromethylphenylhydrazine is employed in place of 3 trifluoromethylphenylhydrazine, there are obtained both isomers of each, namely, methyl a-(S-methoxy-4-trifluoromethyl-3- indolyl) propionate, methyl a-(5-methoxy-6-trifluoromethyl-3-indolyl) propionate; methyl a-(5-butoxy-4-trifluoromethyl-3-indolyl) propionate, methyl a-(S-butoxy- 6-trifiuorom'ethyl-3-indolyl) propionate, methyl a-(S- methyl-6-trifluorornethyl-3-indolyl) propionate, methyl u-(5-methyl-4-trifluoromethyl-3-indolyl) acetate, respectively.

Similarly, when equivalent amounts of Z-trifiuoromethylphenylhydrazine, 4 methoxy 2 trifluorornethylphenylhydrazine, or 4-methyl-2-trifluoromethylphenylhydrazine is employed in place of 3-trifluoromethylphenylhydrazine, there is obtained methyl a-(7-trifluorornethyl-3- indolyl) propionate, methyl a-(5-methoxy-7-trifluoromethyl-3-indolyl)-propionate, or methyl OL-(S -methly-7-trifluoromethyl-3-indolyl) propionate, repectively.

EXAMPLE 3 5 Methyl (2-methyl-4- 0r 6-triflu0r0methyl-3-ind0lyl) acetate When the procedure of Example 40 is followed, using methyl levulinate in place of methyl y -dimethoxybutyrate, there is obtained two isomers, namely, methyl (2-methyl-4-trifluoromethyl-3-indolyl) acetate and methyl (2-methyl-6-trifluoromethyl-3 -indolyl) acetate.

When equivalent amounts of 4-methoxy-3-trifluoromethylphenylhydrazine, 4 butoxy 3 trifluoromethylphenylhydrazine, or 4-methyl-3-trifluoromethylphenylhydrazine is employed in place of 3-trifluoromethylphenylhydrazine, there is obtained both isomers of each, namely, methyl (5 methoxy 2 methyl 4 trifluoromethyl- 3 indolyl)acetate, methyl (5 methoxy 2 methyl- 6-trifluoromethyl-3-indolyl)acetate; methyl (Z-methyl-S- butoxy-4-trifluoromethyl-3-indolyl) acetate, methyl (2- methyl 5 butoxy 6 trifluoromethyl 3 indolyl) acetate; or methyl (2,5-dimethyl-4-trifluoromethyl-3-indolyl) acetate, methyl (2,5-dimethyl-6-trifluoromethyl-3- indolyl) acetate, respectively.

Similarly, when equivalent amounts of 2-trifiuoromethylphenylhydrazine, 4 methoxy 2 trifiuoromethylphenylhydrazine, or 4-methyl-2-trifluoromethylphenylhydrazine is employed in place of 3-trifluoromethylphenylhydrazine, there is obtained methyl (2-methyl-7-trifluoromethyl-3-indolyl)-acetate, methyl (S-methoxy-Z-methyl- 7-tnifluoromethyl-B-indolyl)-acetate, or methyl (2,5-dimethy1-7-trifluoromethyl-3-indolyl) -acetate, respectively.

EXAMPLE 36 Methyl a-(Z-methyl-trifluoromethyl-3-ind0lyl)propionate When the procedure of Example 40 is followed, using methyl a-methyl levulinate in place of methyl-a,a-dimethoxybutyrate, there is obtained two isomers, namely, methyl a(2-methyl-4-trifluoromethyl-3-indolyl) propionate and methyl ot-(Z-methyl6-trifluoromethyl-3-indolyl)- propionate.

When equivalent amounts of 4-methoxy-3-trifiuoromethylphenylhydrazine, or 4-methyl 3 trifluoromethy lphenylhydrazine is employed in place of 3-trifiuoromethy1- phenylhydrazine, there is obtained both isomers of each, namely, methyl a-(S-methoXy 2 methyl 4 trifiuoromethyl-S-indolyl)-propionate, methyl a-(5-rnethoxy2- methyl 6 trifluoromethyl 3 indolyl) propionate; or methyl (2,5 dimethyl 4 trifluoromet'hyl 3 indolyl)-pr-opionate, and methyl a-(2,5-dimethyl-6-trifiuoromethyl-3-indolyl) propionate, respectively.

Similarly, when equivalent quantities of 2-trifluoromethylphenylhydrazine, 4 methoxy 2 trifiuorom'ethylphenylhydrazine, or 4-methyl-2-trifluorometl1ylphenylhydrazine is employed in place of 3-trifluoromethylphenylhydrazine, there is obtained methyl tx-(2-methyl- 7-trifluoromethyl-3-indolyl)-propionate, or methyl ot-(2,5- dimethyl-7-trifluoromethyl-3-indolyl)-propionate, respectively.

EXAMPLE 37 A. A solution of 0.05 mole of methyl (4-trifluoromethyl-3-indo'lyl) acetate and 0.01 mole of sodium in 60 ml. anhydrous benzyl alcohol is slowly fractionated over a period of 4 /2 hours through a Vigreux column to remove methanol. The excess benzyl alcohol is removed by distillation at 60 and 2.5 mm. to give a residue of crude benzyl (4-trifiuoromethyl-3-indolyl) acetate.

B. A suspension of 0.046 mole of 50% sodium hydridemineral oil in 250 ml. of dimethylformamide is stirred for 20 minutes under nitrogen, with ice-cooling. Then 0.035 mole of the benzyl ester obtained above in part A is added and the mixture stirred for 20 minutes. 0.046 mole of p-nitrophenyl 2-methyl-S-trifluoromethyloxazolyl- 4-carboxylate in 50 ml. of dimethylformamide is added dropwise over a period of 30 minutes. The mixture is stirred in an ice-bath for hours under nitrogen, then poured into a mixture of 500 ml. of ether, 5 ml. of acetic acid and 1.1 of iced water. The organic products are extracted with 3 x 300 ml. of ether. The ether solutions are combined and dried over sodium sulfate. The solution is then evaporated to near dryness and the residue charged onto a 300 g. neutral alumina column. The benzyl [1-(2-methyl5-trifluoromethyloxazolyl-4-carbonyl)-4-trifiuoromethyl-3-indolyl] acetate is eluted with ether-petroleum ether (10-50% v./v.).

C. 0.02 mole of the ester obtained in part B is added to 50 ml. of ethyl acetate containing a drop of acetic acid and is reduced catalytically at room temperature in the presence of palladium on charcoal catalyst. Upon completion of the reduction, the catalyst is removed by filtration and the filtrate evaporated to yield 1-(2-methyl- 5 trifluoromethyloxazolyl 4 carbonyl) 4 trifluoromethyl-3-indolyl acetic acid.

When the methyl esters described in Examples 34, 35, 36 and 37 are used in the above procedures, the corre sponding 1 (2 methyl 5 trifiuoromethyloxazolyl 4- carbonyl)-3-indolyl acetic or 3-indolyl-d-propionic acid derivatives are obtained.

When, in the above procedure, the p-nitrophenyl esters of oxazole 4 or 5 carboxylic acids, 2-chlorothiazole carboxylic acid, 5-chloro-2carboxy thiazole or l-benzylimidazole-Z-carboxylic acid are used in place of the 2- methyl-S-trifluoromethyloxazole-4-carboxylate, the corresponding 1-acyl-3-indolyl acids are obtained.

EXAMPLE 38 Methyl [1-(2-mercapt0-thiaz0lyI-S-carbonyl)-2-methyl-5- meth0xy-3-ind0lyl]acetate The procedures of Examples 20A, 20B and 20C are followed, using Z-mercapto-thiazole-S-carboxylic acid in the procedure of Example 20A and the product thereof successively in 20B and 20C, to produce methyl [l-(2- mercapto-thiazolyl 5 carbonyl)-2-methyl-5-methoxy-3- indolyl] acetate.

EXAMPLE 39 0.001 mole of 1-(oxazolyl-4-carbonyl)-5-methoxy-4- trifiuoromethyl-3-indolyl acetic acid is added portion- Wise, with stirring, to 1.5 g. of pyridine hydrochloride at 160-220". On cooling, the residue is dissolved in a small amount of Water, adjusted to pH 6.5 with ammonium hydroxide and diluted with ethanol to precipitate the Zwitter ion, 1-(oxa2olyl-4-carbonyl)-5-hydroxy-4-trifluoromethyl-3'indolyl acetic acid, which is recrystallized from aqueous ethanol.

EXAMPLE 40 Propyl [1 oxazolyl-4-carb0nyl -4-triflu0mmellzyl-3- indolyl] acetate A solution of 0.0054 mole of N,N-dicyclohexylcarbodiimide in 60 ml. of anhydrous tetrahydrofuran is added to a solution of 0.005 mole of 1-(oxazolyl-4-carbonyl)-4-trifluoromethyl-3-indolyl acetic acid and 0.0054 mole of npropyl alcohol in 25 ml. of anhydrous tetrahydrofuran. The reaction mixture is shaken vigorously and allowed to stand at room temperature overnight. The dicyclohexylurea is filtered off and 2 ml. of glacial acetic acid is added to the filtrate. The mixture is allowed to stand for one hour. The solution is filtered and about 200 ml. of ether is added to the filtrate. This filtrate is then extracted well with water. The ether solution is dried over sodium sulfate and concentrated in vacuo. The crude material is chromatographed on neutral alumina using ether-petroleum ether (v./v. 20-50% to obtain propyl 1-(oxazolyl-4-carbonyl) trifluoromethyl- 3-indolyl acetate.

EXAMPLE 41 150 ml. of concentrated HCl is slowly added with stirring to 0.1 mole of 2-fiuoro-4-met.hylaniline. When the temperature of this suspension is at 10, 0.1 mole of 40% sodium nitrite solution is added. The above addition is carried out over 75 minutes, maintaining the temperature below 5. A chilled solution of 0.3 mole of stannous chloride in 75 ml. of concentrated hydrochloric acid is then added, dropwise, to this stirred and cooled diazonium solution, over a period of three hours. During this addition the temperature is maintained at 05 and after the addition the solution is allowed to remain at 0 for several hours. The mixture is then filtered and the cake washed with cold sodium chloride solution. This solid is then added to ml. of saturated sodium acetate solution, extracted with ether and the ether dried. This crude Z-fluoro-4-methylphenylhydrazine is finally isolated and purified as its hydrochloride.

When equivalent amounts of 3-fluoro-4-methylaniline, 2-fluoro-4-methoxyaniline, 3-fluoro-4-methoxyaniline, or is used in the above procedure in place of 2-fluoro-4- methylaniline, there is obtained 3-fiuoro-4-methylphenylhydrazine, 2-fluoro-3-rnethoxyphenylhydrazine, or 3-fluoro-4-methoxyphenylhydrazine, respectively.

23 EXAMPLE 42 Methyl 4 or 6-flu0r0-3-ind0lyl acetate 0.07 mole of 3-fluoropheny1hydrazine and 0.08 mole of methyl 'y,'y-dimethoxybutyrate are added to 250 ml. of 2 N ethanolic hydrogen chloride and the mixture warmed until reaction sets in. After the initial exothermic reaction stops, the mixture is refluxed for about onehalf hour and then concentrated in vacuo to about onethird volume. Four hundred ml. of water are added and the aqueous solution extracted with ether. The ether extracts are washed with sodium bicarbonate solution, water, and then dried over sodium sulfate. The ether solution is concentrated to a small volume in vacuo and chromatographed over 200 g. of acid-washed alumina. The material is eluted with ether-petroleum ether (v./v. 5060%) and distilled in a short-path distillation apparatus. Both isomers, namely, methyl-4-fluoro-3-indolyl acetate and methyl-6-fluoro-3-indolyl acetate are obtained. The structures of these two isomers are differentiated by means of nuclear magnetic resonance spectroscopy.

When an equivalent amount of 3-fluoro-4-methylphenylhydrazine, 3-fluoro-4-methoxyphenylhydrazine, is employed in place of 3-fiuorophenylhydrazine, there is obtained both isomers of each, namely, methyl (4-fiuoro-5- methyl-3-indolyl)acetate, methyl (6-fluoro-5-methyl-3-indolyl)acetate; methyl (4-fluoro-5-methoxy-3-inclolyl)acttate, or methyl (6-fiuoro-5-methoxy-3-indolyl)acetate, respectively.

Similarly, when an equivalent amount of 2-fiuorophenylhydrazine, Z-fluoro-4-methylphenylhydrazine or Z-fiuoro-4-methoxyphenylhydrazine is employed in place of 3- fiuorophenylhydrazine, there is obtained methyl (7-fluoro- 3-indolyl)acetate, methyl (7-fiuoro-5-methyl-3-indolyl) acetate or methyl (7-fiuoro-5-methoxy-3-indoly1)acetate,

respectively.

EXAMPLE 43 Methyl 06*(4 or 6-fluor0-3-ina'olyl) propionate When the procedure of Example 42 is followed, using methyl 'y,'y-dimethoxy-a-methyl-butyrate in place of methyl 'y,' -dimethoxybutyrate, there is obtained two isomers, namely, methyl ot-(4-fiuoro-3-indolyl)-propionate and methyl a-(6-fluoro-3-indolyl)-propionate.

When an equivalent amount of 3-fluoro-4-methylphenylhydrazine, 3-fluoro-4-rnethoxyphenylhydrazine or is employed in place of 3-fluorophenylhydrazine, there is obtained both isomers of each, namely, methyl OL-(4-fiUO1'O- S-methyl- 3 -indolyl)-propionate, methyl a-(6-fluoro-5- methyl-S-indolyl)-propionate; methyl a-(4-fluoro-5-methoxy-3-indolyl)-propionate or methyl a-(6-fluoro-5-methoxy-3aindolyl)-propionate, respectively.

Similarly, when an equivalent amount of 2-fluorophenylhydrazine, 2-fiuoro-4-methylphenylhydrazine or 2-fluoro- 4-methoxyphenylhydrazine is employed in place of 3-fluorophenylhydrazine, there is obtained methyl L-(7- fluoro-3-indolyl) -propionate, methyl oc-(7-fiuoro-5-methyl- 3-indolyl)-propionate or methyl a-(7-fiuoro-5-methoxy-3- indolyl)-propionate, respectively.

EXAMPLE 44 Methyl 4- 0r 6-flu0r0-2-methyl-3-ind0lyl-acetates When the procedure of Example 42 is followed, using methyl levulinate in place of methyl 'y,'y-dimethoxybutyrate, there is obtained two isomers, namely methyl (4-fluoro-2-'nethyl-3-indolyl)-acetate and methyl (6- fluoro-2-methyl-3-indolyl) -acetate.

When an equivalent amount of 3-fluoro-4-methylphenylhydrazine, 3-fluoro-4-methoxyphenylhydrazine, or 3-fiuoro-4-nitrophenylhydrazine is employed in place of 3-fluorophenylhydrazine, there is obtained both isomers of each, namely, methyl (2,5-dimethyl-4-fluoro-3-indolyl)- acetate and methyl (2,5-dimethyl-6-fiuoro-3-indolyl)-acetate; methyl (4-fluoro-5-methoxy-2-methyl-3-indolyl)-acetate, or methyl (G-fluoro--methoxy-2-methyl-3-indolyl)- acetate, respectively.

Similarly, when an equivalent amount of 2-fluorophenylhydrazine, 2-fluoro-4-methylphenylhydrazine or 2-rluoro-4-methoxyphenylhydrazine, is employed in place of 3-fluorophenylhydrazine, there is obtained methyl (7-iluoro2-methyl-3-indolyl)-acetate, methyl (2,5-dimethyl-7-fluoro-3-indolyl)acetate of methyl (7-fluoro- 5-methoxy-2-methyl-3 indolyl)-acetate, respectively.

When the procedure of Example 42 is followed using methyl a-methyl levulinate in place of methyl 'y,'y-dimethoxy-butyrate, there is obtained two isomers, namely, methyl w(4-fiuoro-2-methyl3-indolyl)-propionate and methyl x-(6-fiuoro-2-methyl-3-indolyl)-propionate.

When an equivalent amount of 3-fiuoro-4-methylphenylhydrazine or 3-fiuoro-4-methylphenylhydrazine is employed in place of 3-fluorophenylhydrazine, there is obtained both isomers of each, namely, methyl ot-(2,5-dimethyl-4-fiuoro-3-indolyl)-propionate, methyl a-(2,5-dimethyl-6-fluoro-3-indolyl)-propi0nate; methyl a-(4-fluoro- 5-methoxy-2-methyl-3-indolyl) -propionate or methyl u-(6- fluoro-5-rnethoxy-2-methyl-3-indolyl)-propi0nate, respectively.

In addition, when an equivalent amount of Z-fluorophenylhydrazine, 2-fluoro-4-methylphenylhydrazine or 2-fiuoro 4-methylphenylhydrazine, is employed in place of 3-lluorophenylhydrazine, there is obtained methyl a-(7-fluoro-2-methyl-3-indolyl)-propionate, methyl (IL-(2, 5-dimethyl-7-fluoro-3-indolyl)-propionate or methyl ot-(7- fiuoro-S-methoxy-2-methyl-3-indolyl)-propionate, respectively.

EXAMPLE 45 A. A solution of 0.05 of a mole of methyl (4-fluoro- 3-indolyll-acetate and 0.01 of a mole of sodium in 60 ml. of benzyl alcohol is slowly fractionated over a period of 4 /2 hours through a Vigreux column to remove methanol. The excess benzyl alcohol is then removed by distillation at 60 C. (2.5 mm.) to give a residue of benzyl (4-fiuoro- 3-indolyl)-acetate.

B. A suspension of 0.046 m. of 50% sodium hydridemineral oil in 250 ml. of dimethylformamide is stirred for 20 minutes under nitrogen with ice-cooling. Then 0.035 m. of the benzyl ester obtained in part Z is added and the mixture stirred for 20 minutes. To the above mixture, 0.046 m. of p-nitrophenyl oxazole-4-carboxylate in 50 ml. of dimethylformamide is added dropwise over a period of 30 minutes. The mixture is stirred in an ice-bath for 5 hours under nitrogen. It is then poured into a mixture of 500 ml. of ether, 5 ml. of acetic acid and l l. of ice water. The organic products are extracted with 3 x 300 ml. of ether. The ether solutions are combined and acidified with an ether solution of dry l-lCl. The ether is decanted and the residue is washed with ether and then with aqueous NaHCO The mixture is extracted with ether and the extracts are dried over sodium sulfate. The solution is filtered, evaporated to near dryness and the residue charged onto a 300 g. neutral alumina column. The crude benzyl [1-(oxazolyl-4-carbonyl)-4-fluoro-3-indolyl]acetate is eluted with etherpetroleum ether (10-50% v./v.).

C. 0.02 of a mole of the ester obtained in part B is added to 50 ml. of ethyl acetate containing a drop of acetic acid and is reduced catalytically at room temperature in the presence of palladium on charcoal catalyst. Upon completion of the reduction, the catalyst is removed by filtration and the filtrate evaporated to yield [l-(oxazolyl-4-carbonyl)-4-lluoro-3indolyl]-acetic acid.

EXAMPLE 41 A. (6-methoxy-3-ind0lyl)-acetic anhydride 0.049 mole of dicyclohexylcarbodimide is dissolved in a solution of 0.10 mole of 6-methoxy-3-indolyl acetic acid in 200 ml. of tetrahydrofuran and allowed to stand at room temperature for 2 hours. The precipitated urea is removed by filtration and the filtrate is evaporated in vacuo to a residue and flushed with Skellysolve B. The

residual oily anhydride obtained is used without purification in the next step.

B. (t-Butyl 6-meth0xy-3-ind0lyl) -acetate 25 mls. of t-buty1 alcohol and 0.3 gm. of fused zinc chloride are added to the anhydride from part A. The solution is refluxed for 16 hours and the excess alcohol is removed in vacuo. The residue is then dissolved in ether and washed several times with saturated salt solution. The ether extract is dried over magnesium sulfate and the solution treated with charcoal. The ether solution is then evaporated and flushed several times with Skellysolve B for complete removal of the alcohol. This residual oily ester is used without purification in the next step.

.065 mole of the crude ester, as obtained in step B,

is added to 450 mls. of dimethylformamide and cooled to 4 in an ice bath. .098 mole of a 50% suspension of sodium hydride is added portionwise to this stirred solution. After 15 minutes, 0.085 mole of p-nitrophenyl oxazole-4-carboxylate is added over a 10 minuteinterval. This mixture is then stirred for 9 hours, without replenishing the ice bath. At this time, the mixture is poured into 1 liter of 5% acetic acid and extracted with ether. The ether solution is acidified with an ether solution of dry HCl. The ether is decanted and the residue is washed with ether and then mixed with aqueous NaHCO The mixture is extracted with ether and the ether extract is dried over magnesium sulfate. It is then treated with charcoal and evaporated to a residue. The crude product, thus obtained, is chromatographed on 600 gms. of neutral alumina using a mixture of (v./v -50%) etherpetroleum ether as eluent.

D. 1-(0xaz0lyl-4-carb0nyl)-6-mctlzoxy-3-indolyl acetic acid A mixture of 1.0 g. of the ester obtained in step C. and 0.1 g. powdered porous plate is heated, with stirring, in an oil bath at 210 C. under nitrogen for 2 hours. The product is isolated in the same manner as Example 5D.

E. 1-(0xaz0lyl-4-carb0nyl) -7-meth0xy-3-indolyl acetic acid When the procedure of Parts A, B, C and D is used, starting with 7-methoxy-3-indolyl acetic acid instead of the 6-rnethoxy isomer, there is obtained 1-(oxazolyl-4- carbonyl)-7-methoxy-3-indolyl acetic acid.

EXAMPLE 47 1-(0xaz0lyl-4-carb0nyl) -5,7-dimcthoxy-3-ind0lyl acetic acid A. 5,7-DIMETHOXYGRAMI1NE A solution of 0.032 mole of 5,7-dimethoxyindole in 40 mls. of dioxane is added dropwise, over a period of 30 minutes, to an ice-cooled, stirred mixture of 40 mls. of dioxane, 40 mls. of acetic acid, 3.2 mls. of 36% aqueous formaldehyde and 8.8 mls. of 25% aqueous dimethylamine. The clear solution is stirred and cooled for two hours and then allowed to warm up to room temperature over night. To this solution is added 500 mls. of water. The turbid mixture is then treated with charcoal and filtered through a silicaceous filter aid. The clear filtrate is made alkaline with 400 mls. of dilute sodium hydroxide solution, and placed in a refrigerator, to cool. This mixture is then filtered and the solid gramine is washed with water and dried.

B. 5,7-DIMETHOXYJNDOLYL-3-ACETONITRILE 0.106 mole of the gramine obtained in A is added to 420 mls. of methyl iodide, with vigorous stirring, over a period of minutes. The reaction mixture is then allowed to remain at 5 for 15 hours. The solution is filtered and the iodine metholate cake is dried at 50. This solid is dissolved in a solution of 60 gms. of sodium cyanide in 1 liter of water and warmed for 2 hours at The desired product is extracted with chloroform which is then evaporated to give a crude oily product. The oil is then dissolved in 250 mls. of ether, filtered and the filtrate concentrated. This concentrate is then diluted with petroleum ether, at which point the 5,7-dimethoxyindolyl-3-acetonitrile precipitates. The mixture is then filtered and the cake dried.

C. 5,T-DIMETHOXY-IINDOLYL-S-ACETIC ACID 0.08 mole of the nitrile obtained from B is added to a solution of mls. of alcohol, 100 ml. of water and 4.3 gms. of potassium hydroxide and refluxed for 15 hours. The mixture is brought to room temperature and 60 mls. of glacial acetic acid is added. The solution is then filtered through a tale filter and the filtrate diluted with 500 mls. of water. The precipitated 5,7-dimethoxyindolyl-3-acetic acid is then filtered and dried.

D. 1-(OXAZOLYL-4-CARBONYL)5,7-DIMETHOXY- 3-LNDOLYL A'CETIC ACID The procedure of Example 46A, 46B, 46C and 46D is followed using the product of part C of this example in place of the 6-methoxy-3-indolyl acetic acid, to produce 1-( oxazolyl-4 carbonyl) 5,7 dimethoxy-B-indolyl acid. When 5,6-dimethoxy-3-indolyl acetic acid is used in place of 6-methoxy3-indolyl acetic acid in the above procedure, there is obtained 1-(oxaZolyl-4-carbonyl)-5,6- dimethoxy-3-indolyl acetic acid.

When 5,6-methylenedioxyindole of 2-methyl-6-methoxyindole is used in place of 5,7-dimethoxyindole in the procedure of Parts A, B and C, there is obtained Z-methyl- 6-methoxy-3-indolyl acetic acid or 5,6-methylenedioxy-3- indolyl acetic acid, which, Where used in the procedure of Part D gives 1-(oxazolyl-4-carbonyl) 5,6-methylenedioxy-Lindolyl acetic acid or 1-(oxazolyl-4-c-arbonyl)-2- methyl-6-methoxy-3-indolyl acetic acid.

EXAMPLE 48 Methyl 4-benzyZ0xy-3-ind0lyl acetate A. 4-BENZYLOXY-3-LNDOLYL ACETONITRILE The procedure of Example 47A and 47B is followed, using 4-benzyloxyindole in place of the 5,7-dimethoxyindole, to give 4-benzyloxy-3-indolyl acetonitrile.

B. METHYL 2(4-BENZYLOXY-INDOLYL3)ACETATE A mixture of 0.1 mole of (4-benzyloxyindolyl-3)-acetonitrile in ml. methanol, containing 30 grams dry hydrogen chloride, is refluxed for 2 hours. The reaction mixture is taken to dryness and the residue distributed between 10% sodium bicarbonate solution and chloroform. The chloroform layer is dried with anhydrous sodium sulfate and taken to dryness in. vacuo. The residue is reasonably pure ester.

Similarly, when 7-benzyloxy-3-indolyl acetonitrile is used instead of the 4-isomer, there is obtained methyl 7-benzyloxy-3-indolyl acetate. When S-benyloxy indole and 6-benzyloxy indole are used in the procedure of part A and B of this example, there are produced methyl 5- benzyloxy-3-indolyl acetate and methyl 6-benzyloxy-3- indolyl acetate.

EXAMPLE 49 1'(0xaz0lyl-4-carbonyl)-4-metlz0xy-3dnd0lyl acetic acid A. METHYL rHYDROXY-B-INDOLYL ACETATE A solution of methyl 4-benzyloxy-3-indolyl acetate (4.0 g.) in 150 ml. methanol is shaken with 3 g. palladium on charcoal and hydrogen until the hydrogen uptake ceases. The catalyst is filtered and the filtrate is taken to dryness in vacuo.

B. METHYL 4-METI-IOXY-3-INDOLYL ACETATE A solution of methyl 4-hydroxy-3-indoly1 acetate (10.5 grns, 0.065 m.) in 96 ml. 10% sodium hydroxide is 27 stirred and treated with 7.5 ml. dimethyl sulfate. After stirring for several hours, the crude product is extracted with ether, washed with water and dried over sodium sulfate. The ether solution is evaporated in vacuo and the residue is chromatographed on 200 g. of acid-washed alumina using a mixture of ether-petroleum ether (v./v. 25-50%) as the eluent.

C. d-METHOXY-S-INDOLYL ACETIC ACID A solution of methyl 4-methoxy-3-indolyl acetate in excess 2 N absolute ethanolic potassium hydroxide is allowed to stand overnight, diluted with water and extracted with ether. The aqueous layer is acidified. The precipitate is collected and recrystallized from aqueous ethanol.

D. 1-(OXAZOLYL4-CARBONYL)A4-METHOXIP 3-INDOLYL ACETIC ACID The procedure of Examples 46A, 46B, 46C and 461) is followed using the product of part C in place of 6 methoxy-3-indolyl acetic acid, to product 1-oxa2olyl-4- carbonyl)-4-methoxy-3-indolyl acetic acid.

EXAMPLE 50 1-(0xaz0lyl-4-carb0nyl) -5-chloro-6-mellz0xy-3-ind0lyl acetic acid A. CHLORO-6-METHOXY-3-INDOLYL ACETI'C ACID When 5-chloro-6-methoxy-3-indolylacetonitrile is used in place of 5,7-dimethoxy-indolyl-3-aceto-nitrile, in the procedure of Example 47C, there is obtained 5-chloro-6- methoxy-3-indolyl acetic acid.

B. 1- OXAZOLYLA-CARBONYL) -5-CHLORO-6-METHOXY- 3-INDOLYL ACETIC ACID When the procedures of Example 46A, 46B, 46C and 46D are followed, using 5-chloro-6-methoxy-3-indolyl .acetic acid as the starting material, there is obtained 1 (oxazolyl 4 carbonyl)-5-chl0ro-6-methoxy-3-indolyl acetic acid.

0. 1-(OXAZOLYL-4-CARBONYL)-2-METHYL-7-METHOXY- 3-INDOLYL ACETIC ACID When 2-methyl-7-methoxyindole is used in place of 5,7-dimethoxyindole in the procedures of Example 47A, 47B and 47C and the product is used in the procedures of Examples 46A, 46B, 46C and 46D, there is obtained 1 (oxazolyl 4-carbonyl)-2-methyl-7-methoxy-3-indolyl acetic acid.

EXAMPLE 51 1-(0xaz0lyl-4-carb0nyl) -2-methyl-4-metlz0xy-3-ind0lyl acetic acid A. 2-METHYL-4-METH OXYIND OLE (1) 6-methoxy-Z-nitrobenzoyl clzl0ride.0.046 mole of 6-methoxy-2-nitrobenzoic acid is added to 60 mls. of redistilled thionyl chloride and refluxed for 2 hours. The excess reagent is removed under reduced pressure, maintaining the temperature below 40. The residue is washed with benzene and then removed under reduced pressure. This residue is placed over sodium hydroxide, in vacuo overnight.

(2) Diazomcthyl d-methoxy-Z-nitrophenylketone.-A solution of .044 mole of the 6-methoxy-2-nitrobenzoyl chloride obtained from (1) in 30 mls. of dioxane is added to a solution of 50 mls. of diazomethane in 200 ml. of ether, with agitation at 0. The reaction mixture is allowed to remain overnight at room temperature. The solvent is then removed under reduced pressure to yield a residue containing the ketone. The 6-methoxy-2-nitrophenyl diazomethyl ketone is crystallized from this residue using dioxane.

(3) 6-methoxy-Z-nitroplzenylacetic acid.A solution of .044 mole of the diazoketone obtained in (2) in 75 mls. of dioxane, is added over a period of 20 minutes to a freshly prepared solution of 4.0 gms. of silver oxide, 3.0 gms. of sodium thiosulfate and 5.0 gms. of sodium carbonate in 150 mls. of distilled water. The temperature of the reaction mixture is maintained at 5060 during the addition and for an additional hour. At this point, the mixture is brought to a temperature of 95 for /2 hour. The mixture is then filtered and the filtrate is diluted with 200 mls. of water, acidified with dilute nitric acid and extracted with chloroform (3 x 200 mls.). The combined chloroform extract is washed with 50 mls. of water and dried over sodium sulfate. The chloroform is then removed and the residue extracted with boiling Water (2 x mls.). Concentration of the Water solution, followed by cooling, precipitates the 6-methoxy-2- nitrophenyl acetic acid.

(4) Ethyl-6-methoxy-Z-nitrophenylacetyl mal0nate.- The product from A(3) is used in the procedure of part A(l) to give the corresponding acid chloride. A solution (0.02 mole) of this compound in 25 ml. of ether is gradually added to a refluxing ether solution of ethyl ethoxymagnesiomalonate. Heating is continued until stirring is difficult due to formation of a viscous oil. The cooled mixture is then shaken with dilute H 80 (2.5 g. in 20 ml. H O) until the oily magnesium complex has dissolved. The ethereal phase is separated, washed with water, and dried over Na SO Evaporation yields the crude ethyl-6-methoxy-2-nitrophenylacetylmalonate.

(5) 6-mcth0xy-2-nitroph6nylacet0ne.A solution of 5.7 gms. of the product from A(4), 12 mls. of acetic acid, 1.5 mls. of sulfuric acid and 8 mls. of Water is refluxed for 6 hours. The cooled solution is made alkaline with 5 N sodium hydroxide and extracted with ether (3 x 50 mls.). The combined ethereal extract is Washed with water, dried over sodium sulfate and evaporated to give an oil which rapidly solidifies. Crystallization of this solid from ethanol yields 6-rnethoxy-2-nitrophenylacetone.

(6) 4-meth0xy-2-methylindole.l.2 gms. of the product from A(S) is added to a mixture of 100 mls. of ethyl alcohol and 1.0 gm. of Raney nickel. This solution is shaken at room temperature and atmospheric pressure, in hydrogen for /2 hour. The solution is then filtered and the filtrate evaporated under reduced pressure. Crystallization from light petroleum ether yields 4- methoxy-Z-methylindole.

B. 2METHYL-4-METHOXY-3-INDOLYL ACETIC A'CID When 4-methoxy-2-methylindole is used in place of 5,7-dimethoxyindole as described in Example 47A, 47B and 47C, there is obtained 2-methyl-4-methoxy-3-indolyl acetic acid.

0. 1- OXAZOLYL-4CARBONYL) -2-l\IETHYL4-METHOXY- 3-INDOLYL ACETIC ACID When the product from 51B is used in place of 6- methoxy-3-indolyl acetic acid as described in Example 46A, 46B, 46C and 46D, there is obtained 1-(oxazolyl-4- carbonyl)-2-methyl-4-methoxy-3-indolyl acetic acid.

EXAMPLE 52 1- oxazolyll-carbonyl) -7-meth0xy-5-methyl-3-ind0lyl acetic acid A. 7-METHOXY-5-WIETHYLIND OLE 0.1 mole of 4-methyl-o-anisidine is added to 0.1 mole of monochloroacetaldehyde and the mixture refluxed for 2 hours. The water formed is distilled off and the residue 1s heated at 2l0-220 for an additional hour. This residue is then chromatographed on acid-washed alumina and eluted with ether, petroleum-ether. The eluent is removed under reduced pressure and 7-methoxy-5-rnethylindole is obtained.

B. 1- OXAZOLYL-l-CARBONYL -7-METHOXY-5-METHYL- 3-INDOLYL ACETIC ACID The product from part A is used in the procedures of Example 46A, 46B, 46C and 46D. There is obtained 1 (oxazolyl 4-carbonyl)-7-methoxy-5-methyl-3-indolyl acetic acid.

C. 1-(OXAZOLYL-4-CARBONYL)-5-FLUORO-7-METHOXY- 3 INDOLYL ACETI'C ACID The procedures of parts A and B are followed, starting with 4-fluoro-o-anisidine, to give 1-(oxazoly1-4-carbonyl)- 5-nitro-7-methoxy-3-indolyl acetic acid. When this is used in the procedure of Example 15, there is produced 1- (oxazolyl 4 carbonyl) 5 dimethylamino 7 methoxy-3-indolyl acetic acid.

EXAMPLE 53 1- (xaz0lyl-4-carbonyl) -2-ally l-meth0xy-3-indolyl acetic acid A. '5METHOXY-2-I-NDOLYL ACETALDEHYDE A solution of S-methoxy-Z-indolylacetyl chloride (0.1 mole) in dry tetrahydrofuran is treated with 0.25 mole of lithium aluminum tri-t-butoxy hydride with ice-cooling and stirring. After the initial reaction, the mixture is stirred at room temperature for 4 hours and poured into ice. Excess of acetic acid is added and the product is extracted with ether. The ethereal solution is washed with sodium bicarbonate, dried over sodium sulfate and evaporated to a syrup. Chromatography of the residue on a column of silica gel, using ether-petroleum ether (v./v.) 1030% as eluent, gives 5-methoxy-2-indolyl acetaldeh de.

y B. 2-ALLYL 5-METHOXY INDOLE A solution of 0.1 mole of the aldehyde and 0.12 mole of methylene triphenylphosphine, prepared in situ from 0.12 mole of methyl triphenylphosphonium iodide and 0.12 mole of n-butyl lithium, in benzene is stirred at room temperature for 4 hours and then at 80 for 1 hour. The solution is washed with 0.5 N hydrochloric acid, water and dried over sodium sulfate. Evaporation of the solvent in vacuo and chromatography of the residue on a column of 300 g. acid-washed alumina, using ether-petroleum ether (v./v.) 020% as eluent, gives 2-allyl-5-m e thoxy indole.

C. 2-ALLYL-5-METHOXYGRAMI-NE A solution of 0.032 mole of 2-allyl-5-methoxy indole in 40 ml. of dioxane is added dropwise, over 30 minutes, to an ice-cooled stirred mixture of 40 ml. dioxane, 40 m1. acetic acid, 3.2 ml. 36% aqueous formaldehyde and 8.8 ml. 25% aqueous dimethylamine. The clear solution is stirred and cooled for two hours and then allowed to warm to room temperature overnight. To this solution is added 500 ml. of water. The turbid mixture is then treated with charcoal and filtered through a silicaceous filter aid. The clear filtrate is made alkaline with 400 ml. of dilute NaOH solution and cooled in a refrigerator. The mixture is filtered and the solid gramine is washed with water and dried.

D. 2ALLYL-5-METHOXY-3I-NDOLYL ACETONITRILE 0.106 mole of the gramine from part C is added to 420 ml. of methyl iodide, with vigorous stirring, over a period of 20 minutes. The reaction mixture is then allowed to remain at 5 for hours. The solution is filtered and the iodine metholate cake is dried at 50 C. The solid is dissolved in a solution of 60 g. NaCN in 1 liter and warmed for 2 hours at 80. The desired product is extracted with chloroform which is then evaporated to give a crude oily product. The oil is then dissolved in 250 ml. of ether, filtered and the filtrate is concentrated. The concentrate is diluted with petroleum ether, at which point the 2-allyl-5-methoxy-3-indolyl acetonitrile precipitates. The mixture is filtered and the .cake dried.

E. 2-ALLYL'5-METHOXY-3-INDOLYL ACETIC ACID 0.08 mole of 2-allyl-5-methoxy-3-indolyl acetonitrile is added to a mixture of 140ml. of alcohol, 100 ml. of water and 4.3 g. of KOH. The mixture is refluxed 15 hours and then brought to room temperature. Glacial acetic acid (60 ml.) is added and the solution is filtered through a talc filter. The filtrate is diluted with 500 ml. of water Methyl [1-(1-methyl-5-aminoimidazolel-carboxy)-2- methyl-S-meth0xy-3-ind0lyl] acetate acetic The procedure of Example 19 is followed, using the methyl [1-(1-methyl-5-nitnoimidazole-4-carboxy)-2-methyl-5-methoxy-3-indolyl] acetate prepared in Example 4, to give methyl [1-(1-methyl-5-aminoimidazole-4-carboxy)-2-methyl-5-methoxy-3-indolyl] acetate.

EXAMPLE 55 Methyl [1-(1-methyl-5-dimethylamin0imidaz0le-4- carrboxy -2-methyl-5 -n-1eth0xy-3-ind0lyl] acetate The procedure of Example 15 is followed, using methyl [1 (1 methyl 5 nitroimidazole 4 carboxy) 2- methyl-5-methoxy-3-indolyl] acetate as the starting material, to produce methyl [1-(1-methyl-5-dimethylaminoimidazole 4 carboxy) 2 methyl 5 methoxy 3 indolyl] acetate.

EXAMPLE 5 6 Methyl [1-(5-dimethylamin0ethyl-1,Z-dimethylimidazole- 4 -carboxy -2-methyl-5 -me thoxy-3-in dolyl acetate The procedure of Example 23D is followed, using the methyl [1 (5 cyanomethyl 1,2 dimethylimidazole- 4 carboxy) 2 methyl 5 methoxy 3 indolyl] acetate prepared in Example 4 as the starting material, to pnoduce methyl [1-(5-dimethylan1inoethyl 1,2 dimethylimidazole-4-carboxy)-2-methyl-5-methoxy-3-indolyl] acetate.

When methyl [1-(2-benzyl4-cyano-S-oxazolyl carboxy)-2-methyl-5-methoxy-3-indolyl] acetate is used in this procedure, there is produced methyl [1-(2-benzyl-4- dimethyl aminomethyl-S-oxazolyl carboxy)-Z-methyl-S- methoxy-3-indolyl] acetate.

When the procedure of Example 23C is followed, with the above compounds, the corresponding monomethy-lamino acyl product is obtained.

I claim:

1. A compound of the formula:

3 R TlHF-C OM N R: R

in which R is selected from the group consisting of oxazole, thiazole, imidazole, isoxazole, isothiazole, pyrazole, oxadiazole, thiadiazole and oxazole, thiazole, imid- .azole, isoxazole, isothiazole, pyrazole, oxadiazole, and thiadiazole substituted radicals in which said substituent is selected from the group consisting of halogen, lower .alkyl, lower alkylthio, lower alkenylthio, halogeno-lower allylthio, di(l0wer alkyl)amino lower alkylthio, lower alkoxy, trifluoromethyl, benzyl, phenyl, hydroxy, lower allyl, lower alkoxy, lower alkyl, nitrophenyl, halogenophenyl, anilino, sulfamyl, lower alkanoyl, pyridyl carboxy, carboxamido, cyano, carb-lower alkoxy, cyanomethyl, mercapto, nitro, amino, di(lower alkyl)amino, lower alkyl amino, lower alkanoylamino, hydroxy, amino lower allyl,

benzyloxy, halogeno lower alkanoyl, and di(lower al=kyl)amino, lower alkyl;

R is selected from the group consisting of hydrogen,

lower alkenyl and lower alkyl;

R is selected from the group consisting of hydrogen and lower alkyl;

R, is selected from the group consisting of hydrogen,

lower alkyl, lower alkoxy, fluorine and trifluorometh- Y R is selected from the group consisting of hydrogen, hydroxy, lower alkyl, lower alkoxy, nitro, amino, lower alkylamino, di(lower alkyl) amino, lower alkanoylamino, lower alkanoyl, lower alkylamino, bis- (hydroxy lower alkyl)amino, l-pyrrolidino, 4-methyl-l-piperazinyl, 4-morpholinyl, cyano, amino lower alkyl, di(lower alkyl)amino, lower alkyl, trifluoromethyl, halogen, di(lower alkyl)sulfamyl, benzylthio, lower alkylbenzylthio, lower alkoxybenzylthio, halogenobenzylthio, benzyloxy, lower alkyl benzyloxy, lower alkoxybenzy-loxy, halogenobenzyloxy, lower alkenyl, lower alkenyloxy, l-azacyclopropyl, cyclopropylflower alkoxy)methyloxy, and cyclobutyl(lower alkoxy)methyloxy; and

M is selected from the group consisting of OH, NH henzyloxy, lower alkoxy, OZ where Z is selected from the group consisting of an alkaline metal, an alkaline earth metal, aluminum and magnesium and CY where Y represents the structure:

2. A compound of claim 1 in which R is a halo substituted thiazole radical, R is methyl, R is hydrogen, R is hydrogen, R is methoxy and M is hydroxy.

3. A compound of claim 1 in which R is a halo substituted thiazole radical, R is methyl, R is methyl, R is hydrogen, R is methoxy and M is hydroxy.

4. A compound of claim 1 in which R is a halo substituted thiazole radical, R is methyl, R is hydrogen, R is hydrogen, R is dimethylamino and M is hydroxy.

5. A compound of claim 1 in which R is a halo substituted thiazole radical, R is methyl, R is hydrogen, R is hydrogen, R is fluoro and M is hydroxy.

6. A compound of claim 1 in which R is a lower alkyl substituted isoxazole radical, R is methyl, R is hydrogen, R is hydrogen, R is methoxy and M is hydroxy.

7. A compound of claim 1 in which R is a lower alkyl substituted isoxazole radical, R is methyl, R is methyl, R is hydrogen, R is methoxy and M is hydroxy.

8. A compound of claim 1 in which R is a lower alkyl substituted isoxazole radical, R is methyl, R is hydrogen, R is hydrogen, R is dimethylamino and M is hydroxy.

9. A compound of claim 1 in which R is a lower alkyl substituted isoxazole radical, R is methyl, R is hydrogen, R is hydrogen, R is fluoro and M is hydroxy.

10. A compound of claim 1 in which R is a lower alkyl substituted oxadiazole radical, R is methyl, R is hydrogen, R, is hydrogen, R is methoxy and M is hydroxy.

11. A compound of claim 1 in which R is a lower alkyl substituted oxadiazole radical, R is methyl, R is methyl, R is hydrogen, R is methoxy and M is hydroxy.

12. A compound of claim 1 in which R is a lower alkyl substituted oxadiazole radical, R is methyl, R is hydrogen, R; is hydrogen, R is dimethylamino and M is hydroXy.

13. A compound of claim 1 in which R is a lower alkyl substituted oxadiazole radical, R is methyl, R is hydrogen, R is hydrogen, R is fluoro and M is hydroxy.

14. A compound of claim 1 in which R is a halo substituted imidazole radical, R is methyl, R is hydrogen, R is hydrogen, R is methoxy and M is hydroxy.

15. A compound of claim 1 in which R is a halo substituted imidazole radical, R is methyl, R is methyl, R is hydrogen, R is methoxy and M is hydroxy.

16. A compound of claim 1 in which R is a halo substituted imidazole radical, R is methyl, R is hydrogen, R is hydrogen, R is dimethylamino and M is hydroxy.

17. A compound of claim 1 in which R is a halo substitute-d imidazole radical, R is methyl, R is hydrogen, R is hydrogen, R is fluoro and M is hydroxy.

18. A compound of claim 1 in which R is a lower alkyl substituted isothiazole radical, R is methyl, R is hydrogen, R is hydrogen, R is methoXy and M is hy droxy.

19. A compound of claim 1 in which R is a lower alkyl substituted isothiazole radical, R is methyl, R is methyl, R is hydrogen, R is methoxy and M is hydroxy.

20. A compound of claim 1 in which R is a lower alkyl substituted isothiazole radical, R is methyl, R is hydrogen, R is hydrogen, R is dimethylamino and M is hydroxy.

No references cited.

ALEX MAZEL, Primary Examiner.

HENRY R. JI'LE-S, Examiner.

RICHARD J. GALLAGHER, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,275,644 September 27, 1966 Tsung-Ying Shen It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 51, for "R read R same column 1, between lines 50 and 51, insert R may be hydrogen or lower alkyl;

Signed and sealed this 16th day of July 1968.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

1. A COMPOUND OF THE FORMULA: 